# The Evolution of Marijuana as a Controlled Substance and the Federal-State Policy Gap

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## Record

- **Collection:** Congressional research report
- **Document type:** CRS Report
- **Published:** April 7, 2022
- **Citation:** R44782

## Text

The Evolution of Marijuana as a Controlled
Substance and the Federal-State Policy Gap
Updated April 7, 2022

Congressional Research Service
https://crsreports.congress.gov
R44782

SUMMARY

The Evolution of Marijuana as a Controlled
Substance and the Federal-State Policy Gap

R44782
April 7, 2022
Lisa N. Sacco, Coordinator

Marijuana is a psychoactive drug that generally consists of leaves and flowers of the cannabis
Analyst in Illicit Drugs and
Crime Policy
sativa plant. Its history dates back thousands of years, but in the United States it became popular
as a recreational drug in the early 20 th century. Not long after its rise in popularity, the federal
government began to exercise control over marijuana and other substances through its taxing
authority, and it enacted criminal penalties for violations of drug laws. In 1970, the federal
government enacted the Controlled Substances Act (CSA), which imposed a unified legal
framework at the federal level to regulate certain drugs—whether medical or recreational, and legally or illicitly distributed.
The CSA criminalized the manufacture, distribution, dispensation, and possession of marijuana, which included all of
varieties of cannabis at the time (in 2018, the farm bill [P.L. 115-334] amended the CSA to exclude hemp—plant material
that contains no more than 0.3% delta-9-tetrahydrocannabinol [delta-9-THC] on a dry weight basis).
Under the CSA, marijuana and its derivatives are classified as Schedule I controlled substances, which means the cultivation
(or manufacture), possession, and distribution of marijuana are illegal except for the purposes of sanctioned research. While
the CSA definition of marijuana changed in 2018, which resulted in the removal of hemp from the definition of marijuana,
the status of marijuana as a Schedule I substance has remained unchanged for over 50 years. Many states, however, have
established a range of laws and policies allowing for the medical and recreational use of marijuana over the last several
decades. Most of these states have deviated from an across-the-board prohibition of marijuana, and it is now more the rule
than the exception that states have laws and policies allowing for some cultivation, sale, distribution, and possession of
marijuana or low-THC cannabis—many of which are contrary to the CSA. As of April 1, 2022, 37 states, as well as Puerto
Rico, Guam, the U.S. Virgin Islands, and the District of Columbia, allow for the comprehensive medical use of marijuana,
while 11 additional states allow for the medical use of low-THC cannabis. Also, 18 states, the District of Columbia, Guam,
and the Northern Mariana Islands allow for recreational use of marijuana. These developments have spurred a number of
questions regarding potential implications of the federal and state marijuana policy gap for federal law enforcement activities,
for individuals who comply with state marijuana law but violate federal marijuana law, and for the nation’s drug policies as a
whole.
Under the principles of federalism, the federal government may preempt state marijuana laws and enforce the CSA. Thus far,
the federal response to state actions to legalize marijuana has largely been to allow states to implement their own laws on the
drug. The gap between federal marijuana law and federal enforcement policy and the issues it creates continue each year,
although Congress has partly addressed this gap by restricting the Department of Justice’s (DOJ’s) ability to expend funds to
enforce the CSA in states that allow medical marijuana. DOJ has nonetheless reaffirmed that marijuana growth, trafficking,
and possession remain crimes under federal law irrespective of states’ marijuana laws. To date, federal law enforcement has
generally focused its efforts on criminal networks involved in the illicit marijuana trade.
Many observers voice apprehension over possible negative outcomes of marijuana legalization, including, but not limited to,
(1) potential increases in marijuana use, particularly among youth; (2) potential increases in traffic accidents involving
marijuana-impaired drivers; (3) marijuana trafficking from states that have legalized it into neighboring states that have not;
and (4) U.S. compliance with international treaties. Proponents of legalization have pointed to possible positive outcomes
that could result from marijuana legalization, including a new source of tax revenue for states and a decrease in marijuanarelated arrests that would free up resources for other law enforcement needs. Many states have yet to completely assess the
full range of outcomes of their medical or recreational marijuana programs, particularly those that have only recently
legalized the drug.
The marijuana policy gap creates unique consequences for individuals who act in compliance with state law but violate
federal law. As organizations and individuals have pressed forward with the manufacturing, sale, and use of marijuana,
consequences of the gap have arisen—two of the more publicized consequences for individuals are termination of
employment due to marijuana use in states that have legalized medical or recreational marijuana, and a range of implications
for researchers and postsecondary students on college campuses. Other consequences include, but are not limited to, an
inability to obtain or dismissal from certain types of employment, the inability to purchase and possess a firearm,
inadmissibility for federal housing, and ineligibility for certain visas.

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The Evolution of Marijuana as a Controlled Substance and the Federal-State Policy Gap

The marijuana policy gap between the federal government and states has widened almost every year for over 25 years as
more states legalize medical and/or recreational marijuana. It has only been a few years since states began to legalize
recreational marijuana, but over 25 years since they began to legalize medical marijuana—no state has reversed its
legalization, medical or recreational, since California first legalized medical marijuana in 1996. In addressing state-level
legalization efforts and considering marijuana’s current placement on Schedule I of the CSA, Congress could take one of
several routes. It could elect to take no action, thereby maintaining the federal government’s current marijuana policy and
allowing the policy gap to expand if additional states legalize medical or recreational marijuana. Alternatively, it may decide
that the CSA must be strictly enforced and not allow states to implement marijuana laws that conflict with the CSA. Or, it
may take smaller steps to address the policy gap, such as continuing to include appropriations provisions that restrict DOJ’s
ability to expend funds to enforce federal law.
Congress could also choose to reevaluate marijuana’s classification as a Schedule I controlled substance. If Congress were to
alter the federal status of marijuana by lowering its schedule or even creating a new schedule, it may devote more resources
to the Food and Drug Administration (FDA) to manage and assess the many medical marijuana products available across the
country. If Congress alters marijuana’s schedule, there are a number of issues that policymakers might address. These
include, but are not limited to, issues surrounding availability of financial services for marijuana businesses, federal tax
treatment, and the role of federal law enforcement in marijuana investigations. If Congress chooses to remove marijuana as a
controlled substance under the CSA and remove criminal provisions, this would at least partly eliminate the policy gap with
states that have authorized medical and recreational marijuana programs.
Whether Congress decides to address the gap with the states or not, federal control of cannabis has evolved from the strict
laws and enforcement policies of the 20th century to allowing most states to implement laws authorizing the production and
distribution of marijuana. Among other things, Congress may halt and reverse this evolution, continue to relinquish federal
criminal control, or alter or eliminate federal criminal control of cannabis entirely.

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Contents
Introduction ..................................................................................................................................... 1
Historical Background of Federal Marijuana Policy ....................................................................... 2
Early 20th Century ..................................................................................................................... 3
Mid-20th Century ....................................................................................................................... 3
Controlled Substances Act .................................................................................................. 4
The Shafer Commission...................................................................................................... 6
Marijuana, Late 20th Century and Beyond ................................................................................ 7
The Federal Status of Marijuana and the Expanding Policy Gap with States ................................. 9
State Cannabis Law and Policy Trends ................................................................................... 10
Medical Marijuana ............................................................................................................. 11
Recreational Marijuana ..................................................................................................... 13
Decriminalization.............................................................................................................. 14
Marijuana as Medicine and Federal Involvement ................................................................... 15
Federal Regulation of Marijuana Research ....................................................................... 16
Exemption of Hemp from the CSA and Implications for Hemp and CBD Oil ....................... 19
Change to CSA Definition of Marijuana........................................................................... 20
Marijuana’s Status Moving Forward....................................................................................... 21
Federal Response to State Divergence .......................................................................................... 21
Federalism: Federal Preemption and the Anti-Commandeering Doctrine .............................. 22
Enforcement Focused on Traffickers ...................................................................................... 22
Department of Justice Guidance Memos for U.S. Attorneys ............................................ 23
Monitoring Enforcement Priorities ................................................................................... 26
Limiting Federal Enforcement in States: Directives through Federal Appropriations ............ 26
Federal Financial Laws and Financial Services for Marijuana Businesses ............................. 29
Bank Secrecy Act and Federal Anti-Money Laundering Laws ......................................... 29
FinCEN Guidance to Financial Institutions ...................................................................... 33
Select Outcomes of State Marijuana Legalization ........................................................................ 34
Marijuana Use in the United States ......................................................................................... 35
Marijuana Use in Washington and Colorado .................................................................... 38
Marijuana-Related Traffic Incidents ....................................................................................... 38
Marijuana Arrests .................................................................................................................... 40
Marijuana Trafficking ............................................................................................................. 41
Transnational Trafficking .................................................................................................. 41
Trafficking from States That Have Legalized into Other States ....................................... 42
The Changing Domestic Black Market............................................................................. 43
Legalization Impact on Criminal Proceeds ....................................................................... 44
Tax Revenue ............................................................................................................................ 46
Employment and Educational Consequences of the Marijuana Policy Gap for Individuals ......... 47
Employment and Legal Marijuana Use ................................................................................... 47
Issues for Students at Postsecondary Institutions .................................................................... 49
Federally Required Institutional Drug Abuse Prevention Policies ................................... 49
Student Eligibility for Federal Student Aid....................................................................... 50
International Policy Context and Response ................................................................................... 51
Select Issues For Congress—The Path Forward ........................................................................... 53

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Consideration of Marijuana as a Schedule I Drug: Expand, Minimize, or Eliminate
the Policy Gap ...................................................................................................................... 53
Take No Action Regarding the Gap .................................................................................. 53
Bolster the Federal Position or Expand the Gap ............................................................... 53
Minimize the Gap ............................................................................................................. 54
Eliminate the Gap ............................................................................................................. 56
Provision of Financial Services to the Marijuana Industry ..................................................... 56
Federal Tax Treatment ............................................................................................................. 57
Oversight of Federal Law Enforcement in States that have Legalized Marijuana .................. 59
Review of Agency Missions ............................................................................................. 59
Cooperation with State and Local Law Enforcement ....................................................... 59
Evaluating Federal Enforcement Priorities and Monitoring the Effects of State
Legalization of Marijuana .............................................................................................. 60
Medical Marijuana .................................................................................................................. 61
State Medical Marijuana Laws and Federal Law Enforcement ........................................ 61
State Medical Marijuana Laws and the Department of Veterans Affairs .......................... 62
Conclusion .............................................................................................................................. 62

Figures
Figure 1. Public Opinion on Legalization of Marijuana, 1969-2021 .............................................. 9
Figure 2. State Cannabis Laws ....................................................................................................... 11
Figure 3. Estimates of Current Marijuana Use in Colorado, Washington, and the United
States Overall, 2008-2020 .......................................................................................................... 37

Appendixes
Appendix A. Key Terms Used in the Report ................................................................................. 64
Appendix B. Approved Cannabis-Related Drugs and Research ................................................... 66
Appendix C. Research on Effects of Cannabis Use ...................................................................... 71
Appendix D. Federal Regulation of Hemp and CBD .................................................................... 75
Appendix E. Federalism: Federal Preemption and the Anti-Commandeering Doctrine ............... 81
Appendix F. Monitoring Health Concerns Related to Marijuana in Colorado .............................. 93

Contacts
Author Information........................................................................................................................ 95
Subject Matter Experts .................................................................................................................. 95

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Introduction
Marijuana is a psychoactive drug that generally consists of leaves and flowers of the cannabis
sativa plant. Its history dates back thousands of years, but in the United States it became popular
as a recreational drug in the early 20th century.1 The delta-9-tetrahydrocannabinol (THC) content,
which is the primary (but not the only) psychoactive chemical compound (cannabinoid) in
cannabis,2 is dependent on both the variety of the cannabis plant and the part used (see Appendix
A for definitions of key terms used through this report).
Marijuana is the most commonly used illicit drug in the United States.3 The percentage of the
population 12 and older that reported using marijuana in the past month (i.e., current users) has
generally increased over the last decade—from 6.9% in 2010 to 11.8% in 2020.4 For youth (aged
12-17), the rate of past-month marijuana use over the same time period had some small year-toyear percentage changes, but the rate has remained relatively stable, especially when compared to
adult use rates—the rate of past-month marijuana use among youth was 7.4% in 2010 and 6.7%
in 2020.5 During this time span, nearly half of the youth surveyed had a general perception that
marijuana was relatively easy to acquire if desired.6 Marijuana is readily available throughout
most of the United States; in 2020, most Drug Enforcement Administration (DEA) field divisions
reported that marijuana availability was high in their jurisdictions, and since that time more states
have enacted laws authorizing medical and recreational marijuana programs.7

1 David F. Musto, The American Disease: Origins of Narcotic Control, 3rd ed. (New York: Oxford University Press,

1999), p. 219.
2 Other psychoactive compounds, such as delta-8-THC, are also found in cannabis.
3
In 2020, an estimated 32.8 million individuals in the United States aged 12 or older (11.8% of this population) were
current users of marijuana. The Substance Abuse and Mental Health Services Administration (SAMHSA) defines
current use as having used at least once in the past month. See Department of Health and Human Services (HHS),
SAMHSA, Results from the 2020 National Survey on Drug Use and Health: Detailed Tables, October 2021, Tables
1.1A and 1.1B, https://www.samhsa.gov/data/report/2020-nsduh-detailed-tables (hereinafter, “2020 NSDUH Tables”).
4 For each year from 2010 to 2020, the estimated percentage of the population currently using marijuana was 6.9%,
7.0%, 7.3%, 7.5%, 8.4%, 8.3%, 8.9%, 9.6%, 10.1%, 11.5%, and 11.8% respectively. The difference between each
year’s estimate from 2010 to 2018 and the 2019 estimate (11.5%) is statistically significant at the .05 level. SAMHSA
recommends using caution when comparing estimates between 2020 and prior years because of methodological
changes for 2020. Due to these changes, SAMHSA did not conduct significance testing between 2020 and prior years.
For 2002-2020 data, see 2020 NSDUH Tables, Table 7.3B. Of note, some warn of potential bias in drug usage survey
data because of misreporting by respondents. See Beau Kilmer, Jonathan P. Caulkins, and Gregory Midgette et al.,
Before the Grand Opening: Measuring Washington State’s Marijuana Market in the Last Year Before Legalized
Commercial Sales, RAND Drug Policy Research Center, 2013.
5 For some years the difference from one year’s estimate to the next were not statistically significant at the .05 level.
SAMHSA recommends using caution when comparing estimates between 2020 and prior years because of
methodological changes for 2020. Due to these changes, SAMHSA did not conduct significance testing between 2020
and prior years. See 2020 NSDUH Tables, Table 7.6B.
6 In 2010, nearly half (48.6%) of surveyed youth (ages 12-17) indicated that marijuana would be “fairly easy” or “very
easy” to obtain. In 2020, this figure had decreased to 41.0%. See HHS, SAMHSA, Results from the 2010 National
Survey on Drug Use and Health: Summary of National Findings, September 2011, p. 5; and 2020 NSDUH Tables,
Table 3.1B.
7 Just as the CSA does not distinguish between recreational and medical marijuana (it is all prohibited under the CSA),
DEA does not distinguish between medical and recreational marijuana in discussing its availability, nor does it
distinguish between state-authorized and non-state-authorized marijuana availability. U.S. Department of Justice
(DOJ), Drug Enforcement Administration (DEA), 2020 National Drug Threat Assessment, DEA-DCT-DIR-008-21,
March 2021.

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Under federal law, marijuana and its derivatives8 are classified as Schedule I controlled
substances under the Controlled Substances Act (CSA) unless specifically exempted or listed in
another schedule (see the “Controlled Substances Act” section)—thus, their cultivation,
distribution, or possession, except in the context of approved research studies, is prohibited at the
federal level. In contrast, states have established a range of laws and policies allowing for the
medical and recreational use of marijuana. Most states have deviated from an across-the-board
prohibition of marijuana, and it is now more the rule than the exception that states have laws and
policies allowing for some cultivation, distribution, and possession of marijuana or low-THC
cannabis—many of which are contrary to the CSA. The gap between federal and state laws and
policies on marijuana has expanded each year as states continue to enact laws that allow for the
medical or recreational use of marijuana.
This report provides an historical
Cannabis Terms
background on federal marijuana
The Cannabis sativa plant is often referred to as cannabis, an
umbrella term that includes marijuana and hemp. Marijuana
policy; an overview of state trends
generally refers to the cultivated plant used as a psychotropic
with respect to marijuana
(whether for medicinal or recreational purposes). Hemp,
decriminalization and legalization, for drug
which was removed from the CSA definition of marijuana in 2018,
both medical and recreational uses;
is cultivated for use in the production of a wide range of
and an analysis of the gap between
products, including foods and beverages, personal care products,
dietary supplements, fabrics and textiles, paper, construction
federal and state marijuana law and
materials, and other manufactured and industrial goods. THC and
policy and certain implications and
cannabidiol (CBD) are thought to be the most abundant
consequences of the gap. It reviews
cannabinoids in the Cannabis sativa plant and are among the most
federalism and federal authority to
researched cannabinoids for their potential medical value. While
preempt state marijuana laws and
THC is the primary psychoactive compound found in marijuana,
CBD is a nonpsychoactive compound found in both marijuana and
analyzes relevant issues for federal
hemp.
law enforcement and the
consequences of state marijuana
legalization. The report also outlines a number of related policy questions and options that
Congress may consider, including federal tax treatment of marijuana, financial services for
marijuana businesses, the medical nature of cannabis, oversight of federal law enforcement,
evaluation of marijuana as a Schedule I controlled substance, and some options for addressing the
gap.

Historical Background of Federal Marijuana Policy
To understand the evolution of U.S. marijuana control and the current marijuana policy gap
between the states and the federal government, it is important to examine the history of marijuana
as a controlled substance in the United States.

8 The Agriculture Improvement Act of 2018 (2018 farm bill; P.L. 115-334) removed hemp and hemp derivatives from

the CSA definition of marijuana. Industrial hemp is a variety of the cannabis plant that has low THC content and is
cultivated for use in the production of a wide range of products. Hemp-derived cannabidiol (CBD) is promoted as
treatment for a range of conditions, including epileptic seizures, post-traumatic stress disorder, anxiety, and
inflammation—despite limited scientific evidence to substantiate many of these claims.

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Early 20th Century
Prior to 1937, growing and using marijuana was legal under federal law.9 During the course of
promoting federal legislation to control marijuana, Henry Anslinger, the first commissioner of the
Federal Bureau of Narcotics (FBN),10 and others submitted testimony to Congress regarding the
immorality and harms of marijuana use, claiming that it incited violent and insane behavior.11
Among other observations, Commissioner Anslinger noted that “the major criminal in the United
States is the drug addict; that of all the offenses committed against the laws of this country, the
narcotic addict is the most frequent offender.”12 States had already begun to ban the possession of
marijuana during this time. The federal government created a de facto ban of marijuana under the
Marihuana Tax Act of 1937 (MTA; P.L. 75-238).13 The MTA imposed a high-cost transfer tax
stamp on marijuana sales, but these stamps were rarely issued by the federal government.14
Early 20th Century Marijuana Control
In the early 20th century, enforcement of drug laws was primarily the responsibility of local police, and the Federal
Bureau of Narcotics (FBN) occasionally assisted.15 Due to reduced appropriations during the Great Depression,
the FBN budget and the number of narcotic agents declined and remained low for years. Publicity and warnings of
the dangers of narcotics, in particular marijuana, were primary methods of drug control for the FBN. 16 In seeking
federal control of marijuana and uniform narcotic laws, Commissioner Anslinger and public officials from some
states made personal appeals to civic groups and legislators and pushed for, and received, editorial support in
newspapers; some newspapers maintained a steady stream of anti-marijuana messaging in the 1930s.17

Mid-20th Century
In the decades that followed the enactment of the MTA, Congress continued to pass drug control
legislation and further criminalized drug use. For example, the Boggs Act (P.L. 82-255), passed in
1951, established mandatory prison sentences for some drug offenses, while the Narcotic Control
Act (P.L. 84-728) in 1956 further increased penalties for drug offenses, including marijuana
offenses. In conjunction with growing support for a medical approach to addressing drug abuse,
9 States regulated marijuana, and some banned it prior to 1937.
10 In 1930, the Federal Bureau of Narcotics (FBN) was established within the U.S. Treasury Department to handle

narcotics enforcement.
11 See statements by H. J. Anslinger, Commissioner of Narcotics, Federal Bureau of Narcotics, U.S. Department of the
Treasury, and Dr. James C. Munch, before the U.S. Congress, House Committee on Ways and Means, Taxation of
Marihuana, 75th Cong., 1st sess., April 27-30, May 4, 1937, HRG-1837-WAM-0002.
12 U.S. Congress, House Committee on Ways and Means, Taxation of Marihuana, 75th Cong., 1st sess., April 27-30,
May 4, 1937, HRG-1837-WAM-0002, p. 7.
13 Congressional testimony indicated that marijuana, while it was a problem in the Southwest United States starting in
the mid-1920s, became a “national menace” in the mid-1930s (1935-1937). See statement by H. J. Anslinger,
Commissioner of Narcotics, Federal Bureau of Narcotics, U.S. Department of the Treasury, before the U.S. Congress,
House Committee on Ways and Means, Taxation of Marihuana, 75th Cong., 1st sess., April 27, 1937. In Leary v. United
States (395 U.S. 6 (1968)), the MTA was overturned by the U.S. Supreme Court as a violation of the Fifth
Amendment’s privilege against compelled self-incrimination.
14 Charles F. Levinthal, Drugs, Society, and Criminal Justice, 3rd ed. (New York, NY: Prentice Hall, 2012), p. 58.
15 David F. Musto, The American Disease: Origins of Narcotic Control, 3rd ed. (New York, NY: Oxford University
Press, 1999), pp. 183-200, p. 228.
16 Ibid., p. 214.
17 Richard J. Bonnie and Charles H. Whitebread II, The Marijuana Conviction: A History of Marijuana Conviction in
the United States (New York, NY: The Lindesmith Center, 1999), pp. 94-95; and Eric Schlosser, “Reefer Madness,”
The Atlantic, August 1994.

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there was a strong emphasis on law enforcement control of drugs, including marijuana—which
was gaining popularity as a recreational drug. Congress shifted the constitutional basis for drug
control from its taxing authority to its power to regulate interstate commerce,18 and in 1968 the
FBN merged with the Bureau of Drug Abuse Control and was transferred from Treasury to the
Department of Justice (DOJ).19 Three years later, President Richard Nixon would declare a war
on drugs.20
Congress and President Nixon enhanced federal control of drugs through the enactment of
comprehensive federal drug laws—including the CSA, enacted as Title II of the Comprehensive
Drug Abuse Prevention and Control Act of 1970 (P.L. 91-513). The CSA placed the control of
marijuana and other plant and chemical substances under federal jurisdiction regardless of state
regulations and laws. In designating marijuana as a Schedule I controlled substance, this
legislation officially prohibited the manufacture, distribution, dispensation, and possession of
marijuana except for purposes of sanctioned research.21

Controlled Substances Act
Marijuana’s listing as a Schedule I controlled substance under the CSA22 indicates that the federal
government has determined that
(A) The drug or other substance has a high potential for abuse.
(B) The drug or other substance has no currently accepted medical use in treatment in the
United States.
(C) There is a lack of accepted safety for use of the drug or other substance under medical
supervision.23

Controlled Substances Act (CSA)
The CSA was enacted as Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970.24 It
regulates the manufacture, possession, use, importation, and distribution of certain drugs, substances, and
precursor chemicals. The CSA establishes how the federal government (1) regulates and facilitates the lawful
production, possession, and distribution of controlled substances; (2) prevents diversion25 of these substances for
illegitimate purposes; and (3) penalizes unauthorized activities involving controlled substances.

18 As stated in Article I, Section 8, clause 3 of the U.S. Constitution, “Congress shall have the Power ... To regulate

Commerce with foreign Nations, and among the several States, and with the Indian Tribes.” For more information
about the commerce clause, see CRS Report R43023, Congressional Authority to Enact Criminal Law: An
Examination of Selected Recent Cases.
19 David F. Musto, The American Disease: Origins of Narcotic Control, 3rd ed. (New York, NY: Oxford University
Press, 1999), p. 239. The shift in constitutional authority was part of the Drug Abuse Control Amendments of 1965
(P.L. 89-74).
20 For a broader discussion of the federal government’s drug enforcement history, see CRS Report R43749, Drug
Enforcement in the United States: History, Policy, and Trends.
21 21 U.S.C. §812 and §841. Of note, growing a marijuana plant is considered manufacturing marijuana. Marijuana
(spelled as “marihuana”) is defined under 21 U.S.C. §802(16).
22 For more information on the CSA, see the text box, “Controlled Substances Act (CSA),” and U.S. DOJ, DEA, The
Controlled Substances Act, https://www.dea.gov/controlled-substances-act.
23 21 U.S.C. §812(b)(1).
24 P.L. 91-513; 21 U.S.C. §801 et. seq.
25 DEA has explained that the term diversion, used in the context of the CSA, refers to “the redirection of controlled
substances which may have lawful uses into illicit channels.” Controlled Substances Quotas, 83 Federal Register
32784 (July 16, 2018).

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Under the CSA, there are five schedules under which substances may be classified—Schedule I being the most
restrictive. Substances placed onto one of the five schedules are evaluated on


actual or relative potential for abuse;



known scientific evidence of pharmacological effects;



current scientific knowledge of the substance;



history and current pattern of abuse;



scope, duration, and significance of abuse;



risk to public health;



psychic or physiological dependence liability; and


whether the substance is an immediate precursor of an already scheduled substance.
For an overview of the CSA and a discussion of select legal issues that have arisen under the act, see CRS Report
R45948, The Controlled Substances Act (CSA): A Legal Overview for the 117th Congress.

The CSA places various substances in one of five schedules based on characteristics such as their
medical use, potential for abuse, and safety or dependence liability.26 The five schedules are
progressively ordered, with substances regarded as the least dangerous and addictive classified as
Schedule V and those considered the most dangerous and addictive classified as Schedule I.27 As
described in law, Schedule I substances have “a high potential for abuse” with “no currently
accepted medical use in treatment in the United States” and cannot safely be dispensed under a
prescription.28 Schedule I substances may be lawfully used only for bona fide, federal
government-approved research studies.29
The CSA has two overlapping legal schemes. Registration provisions require entities working
with controlled substances, such as those who research marijuana,30 to register with the
government, take steps to prevent diversion and misuse of controlled substances, and report
certain information to regulators.31 Trafficking provisions establish penalties for the production,
distribution, and possession of controlled substances outside the legitimate scope of the
registration system.32 DEA enforces both registration and trafficking provisions.
A violation of the CSA’s registration requirements—including failure to maintain records or
detect and report suspicious orders, noncompliance with security requirements, or dispensing
controlled substances without the necessary prescriptions—generally does not constitute a
criminal offense unless the violation is committed knowingly. However, in the event of a knowing
violation, DEA may make an arrest and refer the case to the U.S. Attorney’s Office, which may
bring criminal charges against both individual and corporate registrants. A first criminal violation
of the registration requirements by an individual is punishable by a fine and/or up to a year in

26 21 U.S.C. §812(b).
27 When Congress enacted the CSA in 1970, it established “initial schedules” of controlled substances (21 U.S.C.

§812(c), but specified that the schedules “shall be updated” periodically (21 U.S.C. §812(a)). The current list of
controlled substances within their designated schedules may be found in 21 C.F.R. Sections 1308.11–15.
28 21 U.S.C. §812(b).
29 21 U.S.C. §823(f).
30 Every person or entity who manufactures or distributes any controlled substance, such as drug manufacturing
companies, and every person who dispenses any controlled substance, such as doctors and pharmacists, must register
with DEA.
31 21 U.S.C. §§821-832.
32 21 U.S.C. §§841-865.

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prison.33 For other violations of the CSA, potential penalties vary. Trafficking penalties vary
based on the offense and the type and amount of the controlled substance in question, and certain
sections of the CSA define more specific offenses, such as distributing controlled substances near
schools or to individuals under age 21.34 Unauthorized simple possession of a controlled
substance may prompt a minimum fine of $1,000 and a term of up to a year in federal prison.35
Trafficking of large quantities of Schedule I and Schedule II substances carries a prison sentence
of 10 years to life and a fine of up to $10 million for an individual or a fine of up to $50 million
for an organization.36 Penalties increase for second or subsequent offenses, or if death or serious
bodily injury results from the use of the controlled substance. Simple possession penalties are low
compared to trafficking penalties, and DOJ has infrequently pursued simple possession charges
against offenders compared to trafficking charges.37

The Shafer Commission
As part of the CSA enacted in 1970, the National Commission on Marihuana and Drug Abuse,
also known as the Shafer Commission, was established to study marijuana in the United States.38
Specifically, the commission was charged with performing evaluations and examining issues
including, but not limited to,
(A) the extent of use of marihuana in the United States to include its various sources of
users, number of arrests, number of convictions, amount of marihuana seized, type of user,
nature of use;
(B) an evaluation of the efficacy of existing marihuana laws;
(C) a study of the pharmacology of marihuana and its immediate and long-term effects,
both physiological and psychological;
(D) the relationship of marihuana use to aggressive behavior and crime;
(E) the relationship between marihuana and the use of other drugs; and
(F) the international control of marihuana.39

The Shafer Commission, in concluding its review, produced two reports: (1) Marihuana: A Signal
of Misunderstanding, and (2) Drug Use in America: Problem in Perspective.40

33 21 U.S.C. §842(c)(2)(A).
34 See 21 U.S.C. §859, §860.
35 21 U.S.C. §844(a).
36 21 U.S.C. §841(b)(1)(A). For example, trafficking of 1,000 kilograms or more of a mixture or substance containing a

detectable amount of marijuana, or 1,000 or more marijuana plants regardless of weight, would carry this sentence.
37 In FY2020, 98.4% (16,287) of 16,501 federal drug offenses involved drug trafficking. In FY2020, 19.9% (280) of
1,408 federal marijuana offenses involved marijuana possession and 80.1% (1,128) of federal marijuana offenses
involved marijuana trafficking. See U.S. Sentencing Commission, Quick Facts: Drug Trafficking Offenses, June 2021,
https://www.ussc.gov/; and Interactive Data Analyzer, Sentencing Outcomes for FY2020, https://ida.ussc.gov.
38 The commission was composed of two Members of the Senate, two Members of the House, and nine members
appointed by the President of the United States. President Nixon appointed Raymond Shafer as the chairman.
39 P.L. 91-513, §601(d).
40 National Commission on Marihuana and Drug Abuse, Marihuana: A Signal of Misunderstanding, First Report of the
National Commission on Marihuana and Drug Abuse, Washington, DC, March 1972 (hereinafter, “First Report of the
Shafer Commission”); and National Commission on Marihuana and Drug Abuse, Drug Use in America: Problem in
Perspective, Second Report of the National Commission on Marihuana and Drug Abuse, Washington, DC, March 1973
(hereinafter, “Second Report of the Shafer Commission”).

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In its first report (published in 1972), the Shafer Commission discussed the perception of
marijuana as a major social problem and how it came to be viewed as such.41 It made a number of
recommendations, including the development of a “social control policy seeking to discourage
marihuana use, while concentrating primarily on the prevention of heavy and very heavy use.”42
In this first report, the commission also called the application of criminal law in cases of personal
use of marijuana “constitutionally suspect” and declared that “total prohibition is functionally
inappropriate.”43 Of note, none of the recommendations of this report were implemented, either
administratively or legislatively.
In its second report (published in 1973), the Shafer Commission reviewed the use of all drugs in
the United States, not solely marijuana. It examined the origins of the country’s drug problem,
including the social costs of drug use, and once again made specific recommendations regarding
federal and state drug policy. Among its conclusions regarding marijuana, the commission
indicated that aggressive behavior generally cannot be attributed to its use.44 The commission also
reaffirmed its previous findings and recommendations regarding marijuana and added the
following statement:
The risk potential of marihuana is quite low compared to the potent psychoactive
substances, and even its widespread consumption does not involve social cost now
associated with most of the stimulants and depressants (Jones, 1973; Tinklenberg, 1971).
Nonetheless, the Commission remains persuaded that availability of this drug should not
be institutionalized at this time.45

At the conclusion of the second report, the Shafer Commission recommended that Congress
launch a subsequent commission to reexamine the broad issues surrounding drug use and societal
response.46 While a number of congressionally directed commissions regarding drugs have since
been established,47 no such commission has been directed to comprehensively review the issues
of drug use, abuse, and response in the United States.

Marijuana, Late 20th Century and Beyond
While heroin and cocaine were the primary drugs of concern for federal law enforcement during
the 1970s and 80s (respectively), marijuana was also a target of the substantial investment in
enforcement during the federal government’s “war on drugs.”48 In the 1980s, marijuana arrests
were a large part of federal drug enforcement, and there are some federal crime data available to
41 The commission stated that three factors contributed to the perception of marijuana as a major national problem,

including “[1] the illegal behavior is highly visible to all segments of our society, [2] use of the drug is perceived to
threaten the health and morality not only of the individual but of society itself, and [3] most important, the drug has
evolved in the late sixties and early seventies as a symbol of wider social conflicts and public issues.” First Report of
the Shafer Commission, p. 6.
42 First Report of the Shafer Commission, p. 134.
43 Ibid., pp. 142-143.
44 Second Report of the Shafer Commission, p. 158.
45 Ibid, p. 224. In this statement, the Shafer Commission cites the following studies: R.T. Jones, Mental Illness and
Drugs: Pre-Existing Psychopathology and Response to Psychoactive Drugs, Paper Prepared for the National
Commission on Marihuana and Drug Abuse, 1973; and J.R. Tinklenberg, Marihuana and Crime, Paper Prepared for
the National Commission on Marihuana and Drug Abuse, unpublished, October 1971.
46 Second Report of the Shafer Commission, pp. 410-411.
47 See, for example, the President’s Media Commission on Alcohol and Drug Abuse Prevention and the National
Commission on Drug-Free Schools.
48 President Nixon’s war on drugs involved greater emphasis on a law enforcement response to drug crimes.

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illustrate this. The percentage of federal drug offenders charged with marijuana violations was
24% in 1980, increased to 40% in 1982, and decreased to 26% in 1986. Among federal drug
offenders (12,285) charged with marijuana violations (3,221) in 1986, 70% were charged with
distribution, manufacture, or importation, while the remaining 30% were charged with simple
possession.49 Today, the percentage of federal drug offenders charged with marijuana violations is
much lower—in FY2020, 7% of federal drug offenders were marijuana offenders.50
Over the last several decades, federal law enforcement has generally focused its efforts on
criminal networks rather than individual offenders; its current stance regarding drug (particularly
marijuana) offenders appears consistent with this position.51 DOJ has repeatedly emphasized that
marijuana remains an illegal substance under the CSA, but it chooses to focus its enforcement
efforts on the largest threats (e.g., transnational and domestic criminal organizations that traffic
illicit drugs),52 which generally has not included the state-authorized marijuana industries and
individuals in possession of marijuana.
Since the 1990s, the federal government has shifted its stated drug control policy from one that is
more focused on law enforcement to a comprehensive approach—one that focuses on prevention,
treatment, and enforcement.53 Further, sentencing for federal marijuana offenses has become less
severe over the years. For various reasons, the mean prison sentence for federal marijuana
offenses fell from 50 months in FY1992 to 24 months in FY2020.54
U.S. federal drug control policies—specifically those relating to marijuana—continue to generate
debate among policymakers, law enforcement officials, scholars, and the public. Over the last 25
years since California legalized marijuana for medical purposes, the policy conversation for some
has evolved from how strictly marijuana must be prohibited to how much should be allowed.55

49 DOJ, Bureau of Justice Statistics, Federal Offenses and Offenders: Drug Law Violators, 1980-86, June 1988.

Classifications were based on the most serious offense with which the individual was charged at case filing.
50 U.S. Sentencing Commission, 2020 Annual Report and Sourcebook of Federal Sentencing Statistics, Figure D-1. The
U.S. Sentencing Commission derived information about the type of drug from the primary drug type (i.e., the type that
produces the highest base offense level) in the case, and obtained the data from the presentence report, judgment and
commitment order, or plea agreement. See Appendix A.
51 See DOJ, DEA, FY 2021 Performance Budget Congressional Budget Submission; and U.S. Sentencing Commission,
Quick Facts: Drug Trafficking Offenses.
52 DOJ, DEA, 2020 National Drug Threat Assessment, March 2021.
53 See the annual National Drug Control Strategy and accompanying National Drug Control Budget issued by the
Office of National Drug Control Policy.
54 Some reasons for the decline are discussed in U.S. Sentencing Commission, Mandatory Minimum Penalties for Drug
Offenses in the Federal Criminal Justice System, October 2017, https://www.ussc.gov/sites/default/files/pdf/researchand-publications/research-publications/2017/20171025_Drug-Mand-Min.pdf. One reason is that the number of
offenders convicted of a drug crime carrying a mandatory minimum penalty had decreased by 44.7% from FY2010
through FY2016. See U.S. Sentencing Commission, Interactive Data Analyzer, Sentencing Outcomes for FY2020,
https://ida.ussc.gov; and 1996 Sourcebook of Federal Sentencing Statistics, Figures I and U.
55 For example, see U.S. Congress, House Committee on Interstate and Foreign Commerce, Subcommittee on Public
Health and Welfare, Drug Abuse Control Amendments, 1970, Part 1, 91st Cong., February 3-4, 1970; Robert S.
Weppner and James A. Inciardi, “Decriminalizing Marijuana,” International Journal of Offender Therapy and
Comparative Criminology, vol. 22, no. 2 (June 1, 1978), pp. 115-126; U.S. Congress, House Committee on the
Judiciary, Full Committee Markup on H.R. 3884, the “Marijuana Opportunity Reinvestment and Expungement Act,”
116th Cong., 2nd sess., November 21, 2019; and U.S. Congress, House Committee on the Judiciary, Miscellaneous
Measures, Markup of the H.R. 3617, the Marijuana Opportunity Reinvestment and Expungement Act of 2021 or the
MORE Act of 2021 (among other legislation), 117th Cong., 1st sess., September 29, 2021.

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Evolution of Public Opinion
Changes in state and local marijuana laws over time have corresponded with a general shift in public attitudes
toward the substance (see Figure 1). In 1969, 12% of the surveyed population supported legalizing marijuana; in
2021, that percentage had increased to 68% (+/- 3.0 percentage points).56 Much of the shift in public opinion has
occurred over the last 20 years. In addition, 59% (+/- 2.9 percentage points) of respondents indicated in 2015 that
the federal government should not enforce federal marijuana prohibition laws in states that allow for its use.57

Figure 1. Public Opinion on Legalization of Marijuana, 1969-2021

Source: CRS presentation of data from Gallup News Service, Gallup Poll Social Series: Crime,
http://www.gallup.com.
Notes: The question was “Do you think marijuana should be made legal or not?” Sample sizes and margins of
error vary from year to year. Data from 2021 are based on landline and cellular telephone interviews
conducted October 1-19, 2021, with a random sample of 823 adults aged 18 and older living in the United
States.

The Federal Status of Marijuana and the Expanding
Policy Gap with States
In 1970, the CSA placed the control of marijuana under federal jurisdiction regardless of state
regulations and laws, and while the definition of marijuana has recently been amended to exclude
56 The specific question asked was “Do you think marijuana should be made legal or not?” See Gallup, Support for

Legal Marijuana Holds at Record High of 68%, November 4, 2021 (based on poll data from October 2021). For
purposes of this question, the poll does not distinguish between medical and recreational marijuana, nor does Gallup
explain to respondents what “made legal” means. Of note, in September 2019 the Pew Research Center found similar
(67%) levels of support for marijuana use to be legalized among American adults. For this poll, the specific question
was “Do you think that the use of marijuana should be made legal, or not?”; see Andrew Daniller, Two-thirds of
Americans Support Marijuana Legalization, Pew Research Center, November 14, 2019—data from Pew Research
Center’s online American Trends Panel conducted September 3-15, 2019. In a subsequent poll in 2021, Pew asked a
different marijuana legalization question of survey respondents: “Which comes closer to your view about the use of
marijuana by adults?” 60% of respondents chose “[i]t should be legal for medical AND recreational use”; 30% chose
“[i]t should be legal for medical use ONLY”; and 8% chose “[i]t should NOT be legal.” See Ted Van Green,
Americans Overwhelmingly Say Marijuana Should be Legal for Recreational or Medical Use, Pew Research Center,
April 16, 2021—data from a survey of U.S. adults conducted April 5-11, 2021.
57 Pew Research Center for the People & the Press (Pew), In Debate Over Legalizing Marijuana, Disagreement Over
Drug’s Dangers, April 14, 2015 (based on poll data from March 2015). Of note, Pew has not asked about federal
enforcement of marijuana prohibition laws since the 2015 poll.

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hemp and its derivatives, marijuana’s Schedule I classification has remained unchanged for over
50 years. While the federal government maintains marijuana’s current placement as a Schedule I
controlled substance, states have established a range of laws and policies regarding its medical
and recreational use.
To help illustrate the policy gap between the federal government and states, it is useful to
compare the policies for the cultivation and distribution of marijuana. At the federal level, the
cultivation and distribution of marijuana (regardless of whether it is for medical or recreational
purposes) is considered drug trafficking, and the average prison sentence given to an individual
convicted in federal court of marijuana trafficking was 29 months in FY2020.58 In contrast, in
many states the cultivation and distribution of marijuana is lawful and regulated (see Figure 2),
and marijuana businesses that follow state law and regulation can earn profits from the cultivation
and distribution of marijuana.
While the federal government maintains that marijuana has no medicinal value,59 most states and
territories allow for its use as medicine. While the federal government maintains a prohibition on
marijuana because it is believed to have a high potential for abuse and to be a dangerous
substance, 18 states, the District of Columbia (DC), and two territories allow for its recreational
use. Since the federal government amended its definition of marijuana to exclude hemp, farmers
in states have also forged ahead with hemp production, but they must be careful not to cultivate a
product that has a THC value greater than 0.3% or they would instead be cultivating marijuana.

State Cannabis Law and Policy Trends
Over the past few decades, most states have deviated from an across-the-board prohibition of
cannabis. It is now more the rule than the exception that states have laws and policies allowing
for some manufacturing, sale, distribution, and possession of marijuana—all of which are
contrary to the CSA, except for the purposes of sanctioned research.60 Evolving state-level
positions on marijuana include decriminalization measures as well (for definition of terms such as
decriminalization and legalization, see Appendix A). See Figure 2 for a map of the various
cannabis laws by state.

58 U.S. Sentencing Commission, Quick Facts: Marijuana Trafficking Offenses, June 2021, https://www.ussc.gov/.
59 See Appendix C for a discussion FDA and National Academies evaluations for the health effects of marijuana.
60 With the change to the CSA definition of marijuana in the 2018 farm bill, the states that distribute CBD containing

no more than 0.3% THC may not be in violation of the CSA.

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Figure 2. State Cannabis Laws
April 2022

Source: CRS presentation of data from the National Conference of State Legislatures and CRS review of laws
of the 50 states, territories, and District of Columbia (DC).
Notes: Limited-access medical refers to cannabis with low THC content or CBD oil used for a limited list of
medical conditions. State-approved refers to state laws that either (1) allow for recreational and/or medical
marijuana use and/or (2) decriminalize the possession of marijuana in small amounts. Decriminalization refers to a
state’s action to remove accompanying criminal penalties for possession of marijuana in small amounts; however,
civil penalties remain. Of note, some states allow medical marijuana only for certain specified conditions. Further
detail for the states with state-approved recreational use with no retail include the following: (1) While DC has
approved recreational retail of marijuana, Congress has blocked DC from using funds to regulate and tax
marijuana sales; (2) while Vermont has approved recreational use, it does not have a regulatory system for
production or retail; and (3) the remaining states just recently approved recreational marijuana through a ballot
measure and have not yet set up their retail systems. In 2020, South Dakota (SD) voters approved ballot
measures to legalize recreational and medical marijuana, however, in 2021 a circuit court judge ruled the
recreational measure to be unconstitutional. The SD Supreme Court upheld this ruling in 2021. The SD medical
marijuana program is not yet operational. A 2018 Kansas (KS) law allowed for the sale of CBD products with 0%
concentration of THC, but there is some confusion over the legality of CBD in KS because most CBD products
have trace amounts of THC. Of the U.S. territories, Guam (GU) and the Northern Mariana Islands (MP) have
approved recreational marijuana use and retail. GU, Puerto Rico, MP, and the U.S. Virgin Islands (USVI) have
approved medical marijuana use. USVI has also approved decriminalization of marijuana. American Samoa has not
taken any action to either decriminalize marijuana or approve recreational or medical marijuana.

Medical Marijuana
In 1996, California became the first state to amend its drug laws to allow for the medicinal use of
marijuana. As of April 1, 2022, 37 states, the District of Columbia, Puerto Rico, Guam, and the
U.S. Virgin Islands have comprehensive laws and policies allowing for the medicinal use of

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marijuana.61 Eleven additional states allow for “limited-access medical cannabis,” which refers to
cannabis with low THC content or CBD oil used for a limited list of medical conditions.62 Idaho,
Kansas, Nebraska, and American Samoa do not allow either comprehensive medical marijuana or
low-THC cannabis. While the Northern Mariana Islands allow recreational marijuana, it has not
authorized medical marijuana in any capacity.63
As noted, the CSA does not recognize the distinction states are making between the medical and
recreational use of marijuana. Marijuana’s classification as a Schedule I controlled substance
reflects a finding that marijuana has “no currently accepted medical use in treatment in the United
States.”64 Thus, states allowing its use for medical purposes are still at odds with the federal
position. Federal law enforcement officers and attorneys may investigate, arrest, and prosecute
individuals for medical marijuana-related offenses65; however, annual provisions in DOJ
appropriations restrict DOJ’s ability to expend funds to enforce the CSA in states that allow for
medical use of marijuana (see the “Limiting Federal Enforcement in States: Directives through
Federal Appropriations” section; the appropriations provision does not apply to state laws
allowing recreational use of marijuana). Notwithstanding the appropriations rider, marijuanarelated activity in states that allow for it may still result in serious legal consequences under
federal law. DOJ-issued guidance in 2018 reaffirmed the authority of federal prosecutors to
exercise prosecutorial discretion to target federal marijuana offenses “in accordance with all
applicable laws, regulations, and appropriations.”66 DOJ emphasizes the investigation and
prosecution of growers and dispensers who are violating state law and does not target those that
are in compliance with state law and individual users of medical marijuana.67 (Federal
enforcement priorities are discussed further in the “Federal Response to State Divergence”
section.)

61 In November, 2020, Mississippi voters passed a ballot initiative to allow for medical marijuana, but it was overturned

by the Supreme Court of Mississippi on May 14, 2021. On February 2, 2022, a new comprehensive medical marijuana
law was enacted in Mississippi. See National Conference of State Legislatures, State Medical Marijuana Laws,
February 3, 2022. “Comprehensive” medical programs describe those that allow adults to use a range of marijuana
products (not only low-THC cannabis) to treat specified medical issues. Most states specify conditions for which
medical marijuana may be used as treatment. Prior to enactment of the 2018 farm bill, CBD was considered to be
marijuana under the CSA. See the “Change to CSA Definition of Marijuana” section of this report.
62 As previously mentioned, CBD is a chemical compound in marijuana. Unlike THC, it does not have a psychoactive
component.
63 National Conference of State Legislatures, State Medical Marijuana Laws, February 3, 2022 and CRS review of laws
of the 50 states, territories, and District of Columbia (DC).
64 21 U.S.C. §812(b)(1).
65 Several courts have interpreted the appropriations rider to bar DOJ from expending any appropriated funds to
prosecute activities involving marijuana that are conducted in “strict compliance” with state law. See United States v.
McIntosh, 833 F.3d 1163, 1178 (9th Cir. 2016); Duval v. United States, 372 F. Supp. 3d 544, 555-56 (E.D. Mich.
2019); Sandusky v. Goetz, 2018 WL 6505803 at *4-5 (D. Colo. December 11, 2018); United States v. Jackson, 2019
WL 3239844 at *6-8 (E.D. Pa. June 5, 2019). However, activities that fall outside the scope of state medical marijuana
laws remain subject to prosecution. For example, in United States v. Evans, the Ninth Circuit upheld the prosecution of
medical marijuana growers who smoked some of the marijuana they grew because the defendants failed to show they
were “qualifying patients” who acted in strict compliance with state medical marijuana law.
66 Attorney General Jefferson B. Sessions, Memorandum for All United States Attorneys, U.S. Department of Justice,
Marijuana Enforcement, Washington, DC, January 4, 2018.
67 Communication between CRS and DEA on December 29, 2020. See also discussion in the “Enforcement Focused on
Traffickers” section.

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Recreational Marijuana
Recreational marijuana legalization measures remove all state-imposed penalties for specified
activities involving marijuana. As of April 1, 2022, 18 states, DC, Guam, and the Northern
Mariana Islands allow for the recreational use of marijuana. Until 2012, the recreational use of
marijuana had not been legal in any U.S. state since prior to the passage of the CSA in 1970. In
November 2012, citizens of Colorado and Washington voted to legalize, regulate, and tax
marijuana for recreational use.68 In November 2014, recreational marijuana legalization initiatives
also passed in Alaska, Oregon, and DC. Two years later, in November 2016, recreational
marijuana legalization initiatives passed in Massachusetts, California, Maine, and Nevada. In
2018, Michigan voters approved recreational marijuana use through a ballot initiative, and
Vermont approved recreational marijuana use through the legislative process—the first state to
approve recreational marijuana via legislation as opposed to a ballot initiative. In 2019, Illinois
became the second state to enact legislation approving recreational marijuana use. In 2020, voters
in Arizona, Montana, New Jersey, and South Dakota approved measures to allow recreational
marijuana; however, in February 2021 a circuit judge ruled the South Dakota recreational
marijuana measure to be unconstitutional.69 In 2021, New York, Virginia, and Connecticut
approved recreational marijuana through the legislative process.
These recreational marijuana initiatives legalized the possession of specific quantities of
marijuana by individuals aged 21 and over, and (with the exception of DC and Vermont) set up
state-administered regulatory schemes for the sale of marijuana70; however, there are variations
among the initiatives. For example, Alaska, Arizona, California, Colorado, Connecticut,
Massachusetts, Maine, Michigan, Montana, Nevada, New Mexico, Oregon, Vermont, Virginia,
and DC allow individuals to grow their own marijuana plants for recreational use,71 while Illinois,
New Jersey, and Washington do not. Currently, New York allows hemp farmers72 to grow
marijuana for recreational purposes, while all adults age 21 and older will be allowed to grow
their own plants 18 months after retail sales begin in the state.73 Recreational marijuana
legalization initiatives also specify that many activities involving marijuana remain crimes. For
example, in most states that have legalized recreational marijuana, it remains illegal to consume
marijuana in a public place.

68 For more detail regarding both Washington Initiative 502 and Colorado Amendment 64, see CRS Report R43034,

State Legalization of Recreational Marijuana: Selected Legal Issues.
69 On November 24, 2021, the South Dakota Supreme Court upheld this decision. See Teo Armus, “South Dakota
voters said yes to legalizing marijuana. But a judge ruled it’s unconstitutional,” The Washington Post, February 9,
2021; and Jonathan Ellis and Joe Sneve, “South Dakota Supreme Court strikes down recreational marijuana
amendment,” Argus Leader, November 24, 2021.
70 Regulatory schemes include restrictions and requirements for licensing the production, processing, and retail of
marijuana, and procedures for the issuance of licenses.
71 South Dakota’s Constitutional Amendment A would have allowed individuals to grow their own marijuana plants for
recreational use, but a circuit court judge ruled the amendment to be unconstitutional. When New York enacts
regulations for home grown marijuana plants, individuals in the state will be allowed to grow plants as well.
Connecticut will allow for recreational home cultivation beginning July 1, 2023. See Teo Armus, “South Dakota voters
said yes to legalizing marijuana. But a judge ruled it’s unconstitutional,” The Washington Post, February 9, 2021; Don
Cazentre, NewYorkUpstate.com, “Legal marijuana in NY: What you need to know about possession, growing, business
opportunities,” April 6, 2021; and State of Connecticut, Governor Ned Lamont, Governor Lamont Signs Bill Legalizing
and Safely Regulating Adult-Use Cannabis, press releases, June 22, 2021.
72 In order to meet state licensing requirements, farmers must have been growing hemp for at least two of the previous
four years. See NY S.B. 8084.
73 See Marijuana regulation and taxation act, 2021, NY S.B. 854.

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Decriminalization
Marijuana decriminalization differs markedly from legalization. A state decriminalizes conduct
by lowering (e.g., making it a low-level misdemeanor with no possibility of jail time) or
removing the accompanying criminal penalties; however, civil penalties may remain. If, for
instance, a state decriminalizes the possession of marijuana in small amounts,74 possession of it
may still violate state law, but possession of quantities within the specified small amount may be
considered a civil offense and subject to a civil penalty (e.g., a civil fine), not criminal
prosecution. By decriminalizing possession of marijuana in small amounts, states are not
legalizing its possession. Legalizing possession or other conduct involving marijuana would make
that activity legal, or allowable under law, but that is not what decriminalization does. It may
remain a low-level misdemeanor, or it may become a civil or local infraction.
Decriminalization initiatives by the states do not appear to be at odds with the CSA because both
maintain that possessing marijuana is in violation of the law. For example, individuals in
possession of one ounce or less of marijuana in Nebraska are in violation of both the CSA and
Nebraska state law. The difference lies in the associated penalties for these federal and state
violations. Under the CSA, a person convicted of simple possession (first offense) of marijuana
may be punished with up to one year imprisonment and/or fined not more than $1,000.75 Under
Nebraska state law, a person in possession (first offense) of an ounce or less of marijuana is
subject to a civil penalty of not more than $300.76

Decriminalization in Cities
Just as there are disparities between state and federal marijuana laws and policies, some cities’
decriminalization initiatives run contrary to the laws and policies of their states. Several cities
have by law or policy decriminalized marijuana possession independent of what has occurred at
the state level. For example, in November 2014, prior to New York State’s decriminalization of
marijuana possession in 2019, former New York City (NYC) Mayor de Blasio and former-NYC
Police Commissioner Bratton announced a change in marijuana enforcement policy; individuals
found to be in possession of 25 grams or less of marijuana77 may have been eligible to receive a
summons instead of being arrested.78
In Pennsylvania, the state government has not decriminalized marijuana possession,79 but
Pittsburgh, Philadelphia, State College, Harrisburg and other cities in Pennsylvania have all
decriminalized possession in some form. For example, in 2016 Harrisburg’s city council

74 Typically one ounce or less, but the amount varies from state to state.
75

21 U.S.C. §844.

76 Also, the judge may order the offender to attend a drug use and abuse education course. See Section 28-416 of the

Nebraska Revised Statutes.
77 Under NY Pen. Law Section 221.10 in 2014, a person was guilty of criminal possession of marijuana in the fifth
degree when he knowingly and unlawfully possessed “1. marihuana in a public place ... and such marihuana is burning
or open to public view; or 2. one or more preparations, compounds, mixtures or substances containing marihuana and...
are of an aggregate weight of more than twenty-five grams.”
78 City of New York, Transcript: Mayor de Blasio, Police Commissioner Bratton Announce Change in Marijuana
Policy, November 10, 2014.
79 Under Pennsylvania state law, the possession of 30 grams or less of marijuana is a misdemeanor offense punishable
by 30 days in jail and/or a $500 fine.

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unanimously voted to make possession of 30 grams or less of marijuana punishable by a $75 fine
and public use punishable by a $150 fine.80

Marijuana as Medicine and Federal Involvement
During the past 25 years, there have been significant policy shifts at the state level to allow
certain patients to obtain marijuana for medicinal purposes. However, the federal government
does not recognize marijuana as having any currently accepted medical use, and it continues to be
listed on Schedule I under the CSA. Under federal law, a drug must be approved by the Food and
Drug Administration (FDA) before it may be marketed in the United States. To date, FDA has not
approved a marketing application for marijuana for the treatment of any condition. However,
FDA has approved one marijuana-derived drug and three marijuana-related drugs that are
available by prescription. Epidiolex, which contains CBD as its active ingredient, is approved for
the treatment of seizures associated with two rare and severe forms of epilepsy. It is the first (and
only) FDA-approved drug containing a purified drug substance derived from marijuana.81
Following its approval, DEA issued an order placing FDA-approved drugs that contain cannabisderived CBD with no more than 0.1% THC on Schedule V of the CSA, and in April 2020 DEA
notified GW Pharmaceuticals that Epidiolex is no longer subject to the CSA.82 FDA has also
approved two drugs containing synthetic THC (i.e., Marinol [and its generic versions] and
Syndros) and one drug containing a synthetic substance that is structurally similar to THC but not
present in marijuana (i.e., Cesamet). These products are used to treat nausea and vomiting caused
by chemotherapy as well as loss of appetite for individuals with human immunodeficiency virus
(HIV). Additional drugs containing marijuana-derived THC and CBD are reportedly being
developed (see Appendix B for further discussion).83
Although FDA has approved only one marijuana-derived drug and three marijuana-related drugs
for specific purposes, some states allow for dispensing of marijuana for a wide range of medical
conditions. To date, there is insufficient scientific evidence to support claims of the effectiveness
of marijuana for treating many of these conditions. In 2017, the National Academies of Sciences,
Engineering, and Medicine (NASEM) issued a report evaluating the use of cannabis and its
constituent substances for various diseases and conditions (for more information about the report,
see Appendix C). In general, the NASEM found conclusive or substantial evidence that cannabis
or cannabinoids (but not necessarily marijuana or marijuana-derived cannabinoids) are an
effective treatment for chronic pain, chemotherapy-induced nausea and vomiting, and selfreported symptoms of spasticity (i.e., intermittent or constant involuntary muscle movement)
among patients with multiple sclerosis. However, for the remaining conditions examined, the

80 Christine Vendel, “It’s official: Harrisburg council reduces penalties for pot possession,” Penn Live, July 5, 2016;

and City of Harrisburg, City Council.
81 The U.S. Food and Drug Administration (FDA), “FDA approves first drug comprised of an active ingredient derived
from marijuana to treat rare, severe forms of epilepsy,” June 25, 2018, https://www.fda.gov/newsevents/newsroom/
pressannouncements/ucm611046.htm.
82 DOJ, DEA, “Schedules of Controlled Substances: Placement in Schedule V of Certain FDA-Approved Drugs
Containing Cannabidiol; Corresponding Change to Permit Requirements,” 83 Federal Register 48950, September 28,
2018; GW Pharmaceuticals, GW Pharmaceuticals plc and Its U.S. Subsidiary Greenwich Biosciences, Inc. Announce
That EPIDIOLEX® (cannabidiol) Oral Solution Has Been Descheduled And Is No Longer A Controlled Substance,
press release, April 6, 2020, https://ir.gwpharm.com/news-releases/news-release-details/gw-pharmaceuticals-plc-andits-us-subsidiary-greenwich-1.
83 National Institutes of Health (NIH), National Library of Medicine, Clinicaltrials.gov, accessed January 13, 2022,
https://clinicaltrials.gov/ct2/results?cond=&term=Cannabidiol&cntry=&state=&city=&dist=.

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NASEM found insufficient or no evidence of potential therapeutic effects of cannabis or
cannabinoids.
Randomized controlled trials (RCTs) are considered the gold standard of clinical and
epidemiologic research to determine if a proposed treatment (e.g., marijuana) is more effective
than an existing treatment or no treatment (i.e., placebo). As of January 2022, a database
maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH)
lists numerous domestic and international RCTs involving cannabinoids—including THC and
CBD—derived from marijuana as treatment for a variety of conditions, including Amyotrophic
Lateral Sclerosis (ALS), pain, and schizophrenia.84 However, much of this research is in its
nascent stages; therefore, conclusive evidence on the use of marijuana to treat various health
conditions will likely not be available for some time. There are also still many unknowns
regarding how marijuana would be used as a medical treatment if approved, including the
individual and combined clinical benefits of THC, CBD, and other cannabinoids; proper dosage;
and effects of different routes of administration, among others.85 In addition, the short- and longterm health effects of marijuana use are also largely unknown, in part due to the challenges of
researching marijuana in the United States.86

Federal Regulation of Marijuana Research
Conducting research with marijuana involves several federal agencies: DEA, FDA, and the
National Institute on Drug Abuse (NIDA), which is housed within NIH. Before conducting
research with marijuana, an investigator must obtain a DEA registration,87 an FDA review of an
investigational new drug application (IND) or research protocol, and marijuana from NIDA or
another DEA-registered source.88 The U.S. Department of Health and Human Services (HHS) has
issued guidance to aid researchers in conducting medical research on marijuana in compliance
with DEA, FDA, and NIDA requirements if the researcher chooses to obtain their marijuana
through NIDA’s Drug Supply Program (DSP).89 For all controlled substances, researchers must
obtain a registration issued by the Attorney General (DEA, by delegation of authority),90 in
84 See NIH’s database at https://clinicaltrials.gov/ct2/home (accessed January 13, 2022).
85 National Academies of Sciences, Engineering, and Medicine (NASEM), The Health Effects of Cannabis and

Cannabinoids: The Current State of Evidence and Recommendations for Research, Washington, DC, 2017, doi:
10.17226/24625, p. 396.
86 The Schedule I status of marijuana has reportedly created difficulty for researchers who seek to study marijuana but
are potentially unable to meet the strict requirements of the CSA or seek a different strain, potency, or quality of
marijuana for their research than what is lawfully available. See Heike Newman, “Cannabis Clinical Investigations in
Colorado 2019,” Food and Drug Law Institute, July/August 2019; L. Sanders, “The CBD Boom is Way Ahead of the
Science,” Science News, March 27, 2019; and NASEM, The Health Effects of Cannabis and Cannabinoids: The
Current State of Evidence and Recommendations for Research, Washington, DC, 2017, doi: 10.17226/24625, p. 396.
87 A separate, additional registration is needed for Schedule I substances.
88 As of April 1, 2022, there are five federally registered manufacturers of marijuana.
89 DEA has registered additional marijuana growers outside of NIDA’s DSP, and researchers will have options beyond
what is available through the DSP. See DOJ, DEA, “Controls To Enhance the Cultivation of Marihuana for Research in
the United States,” 85 Federal Register 82333-82355, December 18, 2020; and NIH, “Announcement for the
Department of Health and Human Services’ Guidance on Procedures for the Provision of Marijuana for Medical
Research,” May 1999, https://grants.nih.gov/grants/guide/notice-files/not99-091.html. For regulatory requirements
under the CSA, see CRS Report R45948, The Controlled Substances Act (CSA): A Legal Overview for the 117th
Congress.
90 As authorized under 21 U.S.C. Section 871, the Attorney General may delegate any of his/her control and
enforcement functions under the CSA to any DOJ officer or employee—many of these functions are performed by
DEA.

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accordance with relevant federal law and regulations.91 Among other requirements, DEA and
FDA regulations require registrants to comply with strict storage requirements for controlled
substances.92 CSA requirements are most stringent for Schedule I substances (these requirements
are discussed further in Appendix B). In addition to federal requirements, some states require
researchers to comply with state-specific medical or government requirements to conduct clinical
trials or other activities involving Schedule I substances.93
To obtain a DEA registration for purposes of conducting research with a Schedule I controlled
substance (e.g., marijuana), the applicant must submit to DEA a protocol containing specified
information, including a description of the planned research and information about the quantity of
the substance to be used for it.94 DEA must process the registration application and research
protocol and forward a copy of each to the HHS Secretary (FDA, by delegation of authority)
within seven days of receipt. If the Schedule I controlled substance is intended to be studied in
human clinical trials, the researcher must obtain a pre-IND number from FDA, submit the IND to
FDA, and certify to DEA that the IND has been submitted to FDA.95 An IND must include
information about the proposed clinical study design, completed animal test data, and the lead
investigator’s qualifications, among other things.96 For INDs concerning Schedule I controlled
substances, FDA is required, within 30 days of receipt, to review and comment on the scientific
merit of the studies and qualifications of the investigators conducting the research and to report
this information to DEA.97 For a research protocol, FDA must provide this information to DEA
within 21 days of receipt of the protocol.98
If FDA determines that the applicant is qualified and competent and the research protocol is
meritorious, it notifies DEA of such determination. If FDA determines that the protocol is not
meritorious and/or the applicant is not qualified or competent, it must notify DEA of this
determination and provide the reasons for it.99 DEA is required to issue a certificate of registration
within 10 days of receiving FDA’s notice, unless DEA determines that the certificate should be
denied.100 DEA makes the final determination on approving research using Schedule I substances
and drugs.101
91 See 21 U.S.C. §822. This requirement is also described under 21 C.F.R. Section 1301.11(a): “Every person who

manufactures, distributes, dispenses, imports, or exports any controlled substance or who proposes to engage in the
manufacture, distribution, dispensing, importation or exportation of any controlled substance shall obtain a registration
unless exempted by law or pursuant to §§1301.22 through 1301.26.”
92 For the purposes of ensuring the secure storage and distribution of all controlled substances, all applicants and
registrants must generally “provide effective controls and procedures to guard against theft and diversion of controlled
substances.” See 21 C.F.R. §1301.71. FDA’s investigational new drug regulations provide that if the investigational
drug is a controlled substance, the investigator must take adequate precautions, including proper storage of the drug “to
prevent theft or diversion of the substance into illegal channels of distribution.” See 21 C.F.R. §312.69.
93 NASEM, The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations
for Research, Washington, DC, 2017, doi: 10.17226/24625, p. 380.
94 21 C.F.R. §1301.18.
95 NIH, “Announcement for the Department of Health and Human Services’ Guidance on Procedures for the Provision
of Marijuana for Medical Research,” May 1999, https://grants.nih.gov/grants/guide/notice-files/not99-091.html.
96 21 C.F.R. Part 312.
97 21 C.F.R. §1301.32(a).
98 Ibid.
99 21 C.F.R. §1301.32(c).
100 21 C.F.R. §1301.32(b).
101 21 C.F.R. §1301.32; and FDA Manual of Policies and Procedures MAPP 4200.1, “Consulting the Controlled
Substance Staff on INDs and Protocols That Use Schedule I Controlled Substances and Drugs,” https://www.fda.gov/

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Researchers should soon be able to acquire marijuana for research through DEA and its registered
marijuana growers. Currently, researchers may only gain access to marijuana through NIDA. If
researchers continue to access marijuana through NIDA, they must comply with NIH
requirements. NIDA supplies researchers with marijuana from the National Center for Natural
Products Research at the University of Mississippi, which has a contract with NIDA. This was the
only official source in the United States through which researchers could obtain marijuana for
research purposes for over 50 years.102 Researchers who seek to use this source need to make an
inquiry to NIDA to determine availability and associated costs. If NIDA determines that
marijuana is available for the researcher’s study, it will provide the researcher with a letter of
authorization (LOA) to reference NIDA’s marijuana Drug Master File (DMF) on file with
FDA.103 As of April 1, 2022, DEA has five registered manufacturers of marijuana. According to
DEA, researchers will be able to obtain marijuana from these growers with minimal DEA
involvement.104
Some researchers have argued that the federal regulations that guide marijuana research
unnecessarily impede its advancement.105 DOJ and HHS have taken some steps to make
marijuana research easier, including the following:


In June 2015, HHS eliminated one step in obtaining research-grade marijuana for
research that is not funded by NIH. HHS eliminated the Public Health Service
review of non-federally funded research protocols involving marijuana and the
utilization of the existing FDA IND process for drug development.106



In December 2015, DEA announced a waiver to make it easier for researchers
conducting clinical trials with CBD to modify their research protocols and obtain
more CBD than was initially approved.107
In August 2016, DEA announced a new policy intended to increase the number of
approved sources of research-grade marijuana.108



media/71646/download.
102 NIDA, “NIDA’s Role in Providing Marijuana for Research,” https://www.drugabuse.gov/drugs-abuse/marijuana/
nidas-role-in-providing-marijuana-research.
103 A DMF is a submission to FDA “that may be used to provide confidential detailed information about facilities,
processes, or articles used in the manufacturing, processing, packaging, and storing of one or more human drugs.” See
FDA, “Drug Master Files (DMFs),” https://www.fda.gov/drugs/forms-submission-requirements/drug-master-filesdmfs.
104 See DOJ, DEA, “Controls To Enhance the Cultivation of Marihuana for Research in the United States,” 85 Federal
Register 82340, December 18, 2020.
105 See NASEM, The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and
Recommendations for Research, Washington, DC, 2017, doi: 10.17226/24625, p. 382; and Pet. for Writ of Mandamus
at 13, In re Scottsdale Research Inst., No. 19-1120 (D.C. Cir. June 6, 2019).
106 HHS, “Announcement of Revision to the Department of Health and Human Services Guidance on Procedures for
the Provision of Marijuana for Medical Research as Published on May 21, 1999,” 80 Federal Register 35960-35961,
June 23, 2015.
107 DOJ, DEA, “DEA Eases Requirements for FDA-Approved Clinical Trials on Cannabidiol,” press release, December
23, 2015.
108 DOJ, DEA, “Applications to Become Registered under the Controlled Substances Act to Manufacture Marijuana to
Supply Researchers in the U.S.,” 81 Federal Register 53846-53848, August 12, 2016.

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

In August 2019, former Attorney General Barr announced that DEA is “moving
forward with its review of applications for those who seek to grow marijuana
legally to support research.”109



In December 2020, DEA published a final rule that, among other things, requires
all registered manufacturers who cultivate marijuana (for research purposes only)
“to deliver”110 their total crops to DEA with limited exception; however, the
crops may remain at the manufacturers’ registered locations. DEA is to purchase
and take possession of such crops (not later than four months after harvest ends)
by designating a secure storage mechanism at the registered location and
controlling access to the marijuana.111

Some have contended that marijuana provided to researchers is “both qualitatively and
quantitatively inadequate.”112 DEA’s addition of new manufacturers of marijuana may lead to
better quality and a sufficient quantity of marijuana for research purposes. As of April 1, 2022,
DEA has five registered marijuana growers listed on their website.113 (For further discussion of
the marijuana supply policy issue, see Appendix B.)

Exemption of Hemp from the CSA and Implications for Hemp and
CBD Oil
From 1970 until 2018, the federal government’s definition of marijuana included hemp and its
derivatives, and widespread hemp production was generally prohibited. In 2018, Congress
amended the definition to reflect the differences in the chemical and psychoactive properties
between hemp and marijuana.

109

DOJ, DEA, DEA announces steps necessary to improve access to marijuana research, press release, August 25,
2019, https://www.dea.gov/press-releases.
110 The marijuana is not technically delivered to DEA but rather DEA travels to the manufacturer and accepts delivery
at the manufacturer’s registered location, where DEA will maintain possession or designate a different location if
adequate storage does not exist at the manufacturer’s registered location.
111 DOJ, DEA, “Controls To Enhance the Cultivation of Marihuana for Research in the United States,” 85 Federal
Register 82333-82355, December 18, 2020.
112 Marc Kaufman, “Federal Marijuana Monopoly Challenged,” Washington Post, December 12, 2005; and DOJ, DEA,
“Lyle E. Craker; Denial of Application,” 74 Federal Register 2101, January 14, 2009.
113 DOJ, DEA, Diversion Control Division, Marihuana Growers Information, https://www.deadiversion.usdoj.gov/
drugreg/marihuana.htm.

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Distinguishing Between Hemp and Marijuana Plants for Law
Enforcement Purposes
It is difficult for law enforcement to distinguish between hemp and marijuana plants—both are cannabis plants, but
hemp is defined in statute as containing no more than 0.3% delta-9-THC. These plants look, smell, and feel the
same. Drug-sniffing dogs are unable to distinguish between them.114
While a binary roadside test is available to U.S. law enforcement115 to help determine the nature of a product (i.e.,
whether it is hemp or marijuana), a roadside test that gives the exact percentage of THC is not yet available. 116
These precision tests must currently be conducted in a laboratory.

Change to CSA Definition of Marijuana
The 2018 farm bill (P.L. 115-334) amended the CSA to exclude hemp—plant material that
contains no more than 0.3% delta-9 THC on a dry weight basis117—from the statutory definition
of marijuana.118 This provision allows for the cultivation of hemp and hemp-derived products at
or below the 0.3% delta-9 THC threshold,119 as defined in statute, from being regulated as a
Schedule I controlled substance. A DEA registration is no longer required to cultivate or research
hemp and hemp-derived products; however, hemp remains subject to U.S. Department of
Agriculture (USDA) regulation. Further, it remains subject to DEA scrutiny due to the nature of
cannabis and methods of production.120 Changes enacted in the 2018 farm bill now allow for the
cultivation, processing, marketing, and sale of hemp and hemp-derived products that meet the
statutory definition of hemp—if it is produced by an authorized grower in accordance with the
2018 farm bill, associated federal USDA regulations, and applicable state regulations.121 (See
Appendix D for further information regarding federal regulation of hemp production.)

114 Debra Cassens Weiss, “New Hemp Laws Leave Police and Prosecutors Dazed and Confused,” ABA Journal, August

9, 2019.
115 The test turns one color when detecting products with a higher concentration of THC and another color if the
product has low THC. Jodie Fleischer, Katie Leslie, and Steve Jones et al., “New Police Drug Test Aims to Tell Pot
From CBD,” NBC Washington, July 18, 2019; and CRS correspondence with DEA, July 9, 2019.
116 New field tests with more precision are in development. See, for example, Olga Kuchment, “Is it hemp or
marijuana? Scanning technology may provide an instant answer,” AgriLife Today, February 10, 2020.
117 Dry weight basis means the weight of the material after it has been dried at high temperature (generally until
reaching a constant mass).
118 For the CSA definition of marijuana, see 21 U.S.C. §802(16).
119 While Epidiolex—a marijuana-derived drug—contains less than 0.3% delta-9 THC, it was approved and placed in
Schedule V prior to the enactment of the 2018 farm bill (i.e., prior to the change in the statutory definition of
marijuana). As such, despite meeting the current statutory definition of hemp in 7 U.S.C. Section 1639o, it remains in
Schedule V. 83 Federal Register 48950, September 28, 2018.
120 Remaining concerns for farmers and manufacturers of hemp and CBD products are accidental growth of marijuana
plants instead of hemp plants and the THC level changes (sometimes over the 0.3% threshold) during the
manufacturing process. In August 2020, DEA issued an interim final rule to formally provide in their regulations the
scope of DEA regulatory controls over marijuana, THC, and other marijuana-related constituents and acknowledge the
change to the CSA definition of marijuana to exclude hemp and its constituents. See DOJ, DEA, “Implementation of
the Agriculture Improvement Act of 2018,” 85 Federal Register 51639-51645, August 21, 2020.
121 Regulatory plans involving hemp under the oversight of states and tribes will need to include the following
requirements: maintenance of relevant production information; THC testing; procedures for disposal of plants (and
products from those plants) that exceed hemp THC levels; procedures to comply with USDA’s enforcement provisions;
procedures for conducting random, annual inspections of hemp producers; procedures for submitting hemp production
information to USDA; and certification by state and tribal regulators that they have adequate resources and personnel to
implement required procedures.

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Marijuana’s Status Moving Forward
Over the years, several entities have submitted petitions to DEA to reschedule marijuana.122 In
August 2016, after a five-year evaluation process done in conjunction with FDA, DEA rejected
two petitions, one submitted by two state governors and a second submitted by a New Mexico
health provider, to move marijuana to a less-restrictive schedule under the CSA.123 Consistent
with past practice,124 the rejections were based on a conclusion by both FDA and DEA that
marijuana continues to meet the criteria for inclusion on Schedule I—namely that it has a high
potential for abuse, has no currently accepted medical use, and lacks an accepted level of safety
for use, even under medical supervision.125
Congress (through legislation and hearings) has also demonstrated interest in altering the
schedule status of marijuana. In recent years, Members of Congress have introduced various bills
that would change the Schedule I status of marijuana. In the 116th and 117th Congress, for
instance, the House passed the Marijuana Opportunity Reinvestment and Expungement Act of
2019 (MORE Act; H.R. 3884) and the MORE Act of 2021 (H.R. 3617), respectively. The MORE
Act (both H.R. 3884 from the 116th Congress and H.R. 3617 from the 117th Congress) would
remove marijuana from CSA control entirely, among other things. The Senate did not vote on the
MORE Act in the 116th Congress, and as of April 1, 2022, it has not taken up H.R. 3617. Several
other bills that would deschedule or alter the Schedule I status of marijuana have been introduced
in the 117th Congress.

Federal Response to State Divergence
Although state laws do not affect the status of marijuana under federal law or the ability of
federal law enforcement to enforce it, state legalization initiatives have spurred a number of
questions regarding potential implications for federal laws and policies, including federal drug
regulation and enforcement, and banking for marijuana businesses. Thus far, the federal response
to states’ decriminalizing or legalizing marijuana largely has been to allow states to implement
their own laws on the drug. DOJ has nonetheless reaffirmed that marijuana growth, possession,
and trafficking remain crimes under federal law irrespective of states’ marijuana laws. Federal
law enforcement has generally focused its efforts on criminal networks involved in the illicit
marijuana trade. Federal banking regulators have yet to issue any formal guidance in response to
state and local marijuana legalization efforts; however, in February 2014 the Treasury
Department’s Financial Crimes Enforcement Network (FinCEN) issued guidance on financial
institutions’ suspicious activity report requirements when serving marijuana businesses.
122 Any interested party may petition the Administrator of DEA to initiate rulemaking proceedings to reschedule a

controlled substance. See 21 U.S.C. Section 811(a) and 21 C.F.R. Section 1308.43(a) for relevant rules and regulations.
123 In 2011, the governors of Rhode Island and Washington jointly petitioned DEA to have marijuana and “related
items” removed from Schedule I of the CSA and rescheduled as medical cannabis in Schedule II. In 2009, Bryan
Krumm, a health provider in New Mexico, petitioned DEA to have marijuana removed from Schedule I of the CSA and
rescheduled in any schedule other than Schedule I.
124 DEA has previously denied petitions to reschedule marijuana. For example, in 2002 a petition was filed to have
marijuana removed from Schedule I and rescheduled as cannabis in Schedule III, IV, or V. In 2011, DEA rejected the
petition. See DOJ, DEA, “Denial of Petition to Initiate Proceedings to Reschedule Marijuana,” 76 Federal Register
40552-40589, July 8, 2011.
125 See DOJ, DEA, “Denial of Petition to Initiate Proceedings to Reschedule Marijuana,” 81 Federal Register 5376753845, August 12, 2016; and DOJ, DEA, “Denial of Petition to Initiate Proceedings to Reschedule Marijuana,” 81
Federal Register 53687-53766, August 12, 2016.

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Federalism: Federal Preemption and the Anti-Commandeering
Doctrine126
The gap between the federal CSA,127 which criminalizes the cultivation, distribution, and
possession of marijuana, and certain state marijuana laws, which authorize some of those same
activities, raises questions regarding “the proper division of authority between the Federal
Government and the States”128 under both the preemption and anti-commandeering doctrines. The
Supremacy Clause of the U.S. Constitution generally establishes that federal law is supreme to,
and may preempt, conflicting state laws.129 However, the federal government’s preemptive
authority is subject to certain limitations, including the anti-commandeering doctrine, which
generally prohibits the federal government from forcing states to perform regulatory activities on
the federal government’s behalf.130 See Appendix E for a comprehensive legal discussion of the
federal preemption and anti-commandeering doctrines, and how the courts have handled the
conflict between federal CSA and state marijuana laws.

Enforcement Focused on Traffickers
Federal law enforcement generally focuses its counterdrug efforts on criminal networks involved
in the illicit drug trade. Federal marijuana enforcement efforts, largely focused on traffickers and
distributors of marijuana rather than users, appear to be consistent with this position.131 Arrests
for marijuana possession offenses are largely made by state and local police.132 President Barack
Obama once noted that “[it] would not make sense from a prioritization point of view for us to
focus on recreational drug users in a state that has already said that under state law
that’s legal.”133 Officials in the Trump Administration also indicated that prosecuting traffickers
over users was a priority; and while there was some uncertainty about the future of marijuana
policy under the Trump Administration, then-Attorney General Sessions noted that federal law
126 This section was authored by David H. Carpenter, Legislative Attorney in CRS’s American Law Division (ALD). It

uses citation and other editorial styles consistent with ALD’s reports.
127 Comprehensive Drug Abuse Prevention and Control Act of 1970, Pub. L. No. 91-513, Title II, 84 Stat. 1236, 1242
(codified as amended at 21 U.S.C. §§ 801–904).
128 New York v. United States, 505 U.S. 144, 149 (1992).
129 U.S. CONST. art. VI, cl. 2.
130 Murphy v. NCAA, 138 S. Ct. 1461, 1476 (2019) (“The legislative powers granted to Congress are sizable, but they
are not unlimited. The Constitution confers on Congress not plenary legislative power but only certain enumerated
powers. Therefore, all other legislative power is reserved for the States, as the Tenth Amendment confirms. And
conspicuously absent from the list of powers given to Congress is the power to issue direct orders to the governments
of the States. The anticommandeering doctrine simply represents the recognition of this limit on congressional
authority.”).
131 DEA’s mission “is to enforce the controlled substances laws and regulations of the United States and bring to the
criminal and civil justice system of the United States, or any other competent jurisdiction, those organizations and
principal members of organizations, involved in the growing, manufacture, or distribution of controlled substances
appearing in or destined for illicit traffic in the United States; and to recommend and support non-enforcement
programs aimed at reducing the availability of illicit controlled substances on the domestic and international markets.”
See https://www.dea.gov/mission.
132 In 2015, the Government Accountability Office concluded that DOJ has not historically targeted possession of small
amounts of marijuana for personal use on private property, and has left lower-level marijuana activity to state and local
law enforcement authorities through enforcement of their own drug laws. See U.S. Government Accountability Office
(GAO), State Marijuana Legalization: DOJ Should Document Its Approach to Monitoring the Effects of Legalization,
GAO-16-1, December 2015, p. 9.
133 “Marijuana Not High Obama Priority,” ABC Nightline, December 14, 2012.

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enforcement would continue to focus their marijuana-related enforcement efforts on criminal
organizations over “routine cases.”134 Similarly, then-Attorney General Barr noted he would
continue to “prioritize the prosecution of significant drug traffickers, rather than drug users or
low-level drug offenders.”135 During his 2021 Senate confirmation hearing, Attorney General
Garland indicated that the Biden Administration will maintain this position.136

Department of Justice Guidance Memos for U.S. Attorneys
DOJ has articulated federal marijuana enforcement policy through several memoranda providing
direction for U.S. Attorneys in states that have medical use of marijuana programs. After states
began to legalize the medical use of marijuana, DOJ reaffirmed that marijuana growth,
possession, and trafficking remain crimes under federal law irrespective of state law.137 In 2009,
former Deputy Attorney General David Ogden authored a memo for selected U.S. Attorneys that
reiterated that combating major drug traffickers remains a central priority and stated:
[t]he prosecution of significant traffickers of illegal drugs, including marijuana, and the
disruption of illegal drug manufacturing and trafficking networks continues to be a core
priority in the [Justice] Department’s efforts against narcotics and dangerous drugs, and
the Department’s investigative and prosecutorial resources should be directed towards
these objectives. As a general matter, pursuit of these priorities should not focus federal
resources in your States on individuals whose actions are in clear and unambiguous
compliance with existing state laws providing for the medical use of marijuana. 138

In a follow-up memorandum to U.S. Attorneys in 2011, former Deputy Attorney General James
Cole restated that enforcing the CSA remained a core priority of DOJ, even in states that had
legalized medical marijuana. He clarified that “[t]he Ogden Memorandum was never intended to
shield such activities from federal enforcement action and prosecution, even where those
activities purport to comply with state law.”139 Deputy Attorney General Cole warned those who
might assist medical marijuana dispensaries in any way that “[p]ersons who are in the business of
cultivating, selling or distributing marijuana, and those who knowingly facilitate such activities
[emphasis added], are in violation of the Controlled Substances Act, regardless of state law.”140
This has been interpreted by some to mean, for example, that building owners and managers are
in violation of the CSA if they allow medical marijuana dispensaries to operate in their
134 Remarks by Attorney General Jeff Sessions at a Georgetown Law student symposium hosted by the Federalist

Society, March 10, 2018, https://www.c-span.org/video/?442403-1/attorney-general-jeff-sessions-judicial-authority. He
stated that federal law enforcement would not be able to, even if it wished to, take over “state enforcement of routine
[marijuana] cases.”
135 William P. Barr, “Questions for the Record, William P. Barr, Nominee to be United States Attorney General,”
January 27, 2019.
136 U.S. Congress, Senate Committee on the Judiciary, The Nomination of the Honorable Merrick Brian Garland to be
Attorney General of the United States: Responses to Questions for the Record to Judge Merrick Garland, Nominee to
be United States Attorney General, 117th Cong., 1st sess., February 2021, pp. 23-25.
137 United States Attorney’s Office, “Statement From U.S. Attorney’s Office on Initiative 502,” press release,
December 5, 2012.
138 Deputy Attorney General David W. Ogden, Memorandum for Selected United States Attorneys, U.S. Department of
Justice, Investigations and Prosecutions in States Authorizing the Medical Use of Marijuana, Washington, DC, October
19, 2009, pp. 1-2.
139 Deputy Attorney General James M. Cole, Memorandum for United States Attorneys, U.S. Department of Justice,
Guidance Regarding the Ogden Memo in Jurisdictions Seeking to Authorize Marijuana for Medical Use, Washington,
DC, June 29, 2011, p. 2.
140 Ibid.

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buildings.141 Deputy Attorney General Cole further warned that “[t]hose who engage in
transactions involving the proceeds of such activity [cultivating, selling, or distributing of
marijuana] may be in violation of federal money laundering statutes and other federal financial
laws.”142
In an August 2013 memorandum (the Cole memorandum), Deputy Attorney General Cole stated
that while marijuana remains an illegal substance under the CSA, DOJ would focus its resources
on the “most significant threats in the most effective, consistent, and rational way,” and outlined
eight marijuana enforcement priorities for DOJ: 143



preventing the distribution of marijuana to minors;
preventing revenue from the sale of marijuana from going to criminal enterprises,
gangs, and cartels;



preventing the diversion of marijuana from states where it is legal under state law
in some form to other states;
preventing state-authorized marijuana activity from being used as a cover or
pretext for the trafficking of other illegal drugs or other illegal activity;
preventing violence and the use of firearms in the cultivation and distribution of
marijuana;








preventing drugged driving and the exacerbation of other adverse public health
consequences associated with marijuana use;
preventing the growing of marijuana on public lands and the attendant public
safety and environmental dangers posed by marijuana production on public
lands; and
preventing marijuana possession or use on federal property.144

In a February 2014 memorandum, Deputy Attorney General Cole further reinforced these
enforcement priorities, specifically as they related to the prosecution of marijuana-related
financial crimes. This memorandum directed the U.S. Attorneys that “in determining whether to
charge individuals or institutions with ... [certain financial] offenses based on marijuana-related
violations of the CSA, prosecutors should apply the eight enforcement priorities described in the
August 29 guidance.”145
In October 2014, DOJ released another memorandum to the U.S. Attorneys that asserted the
applicability of the eight enforcement priorities in Indian Country.146 It responded to the tribes’
requests for guidance on CSA enforcement on tribal lands. DOJ reiterated that the 2013 Cole
141 Jennifer Medina, “U.S. Attorneys in California Set Crackdown on Marijuana,” New York Times, October 8, 2011, p.

10.
142 Deputy Attorney General James M. Cole, Memorandum for United States Attorneys, U.S. Department of Justice,
Guidance Regarding the Ogden Memo in Jurisdictions Seeking to Authorize Marijuana for Medical Use, Washington,
DC, June 29, 2011, p. 2.
143 Deputy Attorney General James M. Cole, Memorandum for all United States Attorneys, U.S. Department of Justice,
Guidance Regarding Marijuana Enforcement, Washington, DC, August 29, 2013, p. 1.
144 Ibid., pp. 1-2.
145 Deputy Attorney General James M. Cole, Memorandum for All United States Attorneys, U.S. Department of Justice,
Guidance Regarding Marijuana Related Financial Crimes, Washington, DC, February 14, 2014, p. 2.
146 Executive Office for United States Attorneys, Policy Statement Regarding Marijuana Issues in Indian Country,
October 28, 2014.

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memorandum did not prohibit the federal government from enforcing federal law in Indian
Country, and added the following:
The eight priorities in the Cole Memorandum will guide United States Attorneys’
marijuana enforcement efforts in Indian Country, including in the event that sovereign
Indian Nations seek to legalize the cultivation or use of marijuana in Indian Country
[emphasis added].147

Unlike the Cole memorandum, DOJ did not specifically refer to distribution and regulation of
marijuana. It was unclear whether distribution of marijuana would be tolerated on tribal lands
should tribal governments seek to legalize and distribute marijuana. Despite the lack of clarity,
some tribes moved forward with plans to grow and sell marijuana at tribe-owned stores on tribal
lands.148 Since the memo was released, DEA has led some marijuana enforcement actions on
tribal lands involving tribe-authorized marijuana activity.149
In January 2018, DOJ issued another memorandum (Sessions memorandum) to the U.S.
Attorneys on marijuana enforcement. In it, then-Attorney General Sessions emphasized the CSA
prohibition of marijuana cultivation, distribution, and possession and its associated penalties. He
also pointed out that these marijuana activities may “serve as the basis for the prosecution of
other crimes, such as those prohibited by the money laundering statutes, the unlicensed money
transmitter statute, and the Bank Secrecy Act…. [T]hese statutes reflect Congress’s determination
that marijuana is a dangerous drug and that marijuana activity is a serious crime.”150 Sessions also
noted in the memorandum that DOJ had “well-established principles” dating back to 1980 to
decide which marijuana activities to prosecute, and because these principles exist, the previous
DOJ memoranda were unnecessary and rescinded.151
While DOJ has not released additional memoranda on marijuana enforcement since the Sessions
memorandum, then-Attorney General Barr indicated his discomfort with “ignoring the
enforcement of federal law.”152 On the other hand, Barr also stated during his nomination hearing
that he did not intend to target marijuana businesses that had relied on the Cole memorandum for
guidance.153 Attorney General Garland stated the following in his official responses to questions
147 Monty Wilkinson, Memorandum, U.S. Department of Justice, Policy Statement Regarding Marijuana Issues in

Indian Country, Washington, DC, October 28, 2014.
148 “Native American Tribes Approve Plan to Grow and Sell Marijuana in Oregon,” The New York Times, December
19, 2015; Jackie Valley, “Las Vegas Paiutes’ Newest Venture: Medical Marijuana,” Las Vegas Sun, March 1, 2016;
Noelle Crombie, “Warm Springs Tribes Launch Ambitious Pot Venture, Hope for Economic Windfall,” The Oregonian
- Oregon Live, April 29, 2016; John Gillie, “Two Marijuana Retailers Opening Soon in City that Still Bans Cannabis
Sales,” The News Tribune, January 28, 2017; Saint Regis Mohawk Tribal Council, Tribal Election Board Certifies
Medical Marijuana Ordinance and Adult Use (Recreational) Marijuana Referendum Results, December 23, 2019,
https://www.srmt-nsn.gov/; and Dalton Walker, “Red Lake Nation approves medical cannabis,” Red Lake Nation News,
May 29, 2020.
149 Steven Nelson, “DEA Raid on Tribe’s Cannabis Crop Infuriates and Confuses Reformers,” U.S. News & World
Report, October 26, 2015; and Cary Spivak, “Milwaukee Journal Sentinel,” November 18, 2015.
150 Attorney General Jefferson B. Sessions, Memorandum for All United States Attorneys, U.S. Department of Justice,
Marijuana Enforcement, Washington, DC, January 4, 2018.
151 Ibid.
152 See comments made by former Attorney General Barr in response to questioning from Senator Murkowski, U.S.
Congress, Senate Committee on Appropriations, Subcommittee on Commerce, Justice, Science, and Related Agencies,
Hearing to review the Fiscal Year 2020 funding request and budget justification for the U.S. Department of Justice,
116th Cong., 2nd sess., April 10, 2019.
153 See comments made by former Attorney General Barr in response to questioning from Senator Booker, U.S.
Congress, Senate Committee on the Judiciary, Nomination of the Honorable William Pelham Barr to be Attorney
General of the United States, 116th Cong., 1st sess., January 15, 2019.

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from his Senate confirmation hearing: “I do not think it the best use of the Department’s [DOJ’s]
limited resources to pursue prosecutions of those who are complying with the laws in states that
have legalized and are effectively regulating marijuana.”154

Monitoring Enforcement Priorities
In a 2015 review of the DOJ memoranda and evaluation of DOJ efforts to monitor effects of state
legalization relative to DOJ guidance (which predated the Sessions memorandum), the
Government Accountability Office (GAO) concluded that “DOJ has not historically devoted
resources to prosecuting individuals whose conduct is limited to possession of small amounts of
marijuana for personal use on private property. Rather, DOJ has left such lower-level or localized
marijuana activity to state and local law enforcement authorities through enforcement of their
own drug laws.”155 GAO recommended that DOJ monitor the effects of state-level marijuana
legalization initiatives relative to the eight DOJ enforcement priorities outlined in the Cole
memorandum. GAO’s evaluation noted that DOJ was already taking a number of steps to help
assess these effects. For instance, DOJ indicated that U.S. Attorneys were in contact with officials
in states that had legalized marijuana, and through these interactions could communicate federal
enforcement priorities, assess the implications of legalization relative to the priorities, and
identify specific areas of federal concern. In addition, DOJ reported that it relies upon information
from sources such as “federal surveys on drug use; state and local research; and feedback from
federal, state, and local law enforcement” to assess the effects of state-level legalization
initiatives.156 GAO concluded that DOJ had not documented its specific monitoring process, and
recommended that DOJ develop a “clear plan” for how it will monitor and document the effects
of state marijuana legalization on federal enforcement priorities.157 Since the Sessions
memorandum rescinded the previous DOJ guidance memos (which included the enforcement
priorities GAO focused on), DOJ has not indicated whether it monitors and documents the effects
of state marijuana legalization on federal enforcement priorities.

Limiting Federal Enforcement in States: Directives through Federal
Appropriations158
In each fiscal year since FY2015, Congress has included provisions in appropriations acts that
prohibit DOJ from using appropriated funds to prevent certain states and territories and the
District of Columbia from “implementing their own laws that authorize the use, distribution,
possession, or cultivation of medical marijuana.”159
154 U.S. Congress, Senate Committee on the Judiciary, The Nomination of the Honorable Merrick Brian Garland to be

Attorney General of the United States: Responses to Questions for the Record to Judge Merrick Garland, Nominee to
be United States Attorney General, 117th Cong., 1st sess., February 2021, pp. 23-25.
155 U.S. Government Accountability Office, State Marijuana Legalization: DOJ Should Document Its Approach to
Monitoring the Effects of Legalization, GAO-16-1, December 2015, p. 9.
156 Ibid., p. 27.
157 Ibid.
158 This section was authored by Joanna Lampe, Legislative Attorney in CRS’s American Law Division (ALD). It uses
citation and other editorial styles consistent with ALD’s reports.
159 See Consolidated and Further Continuing Appropriations Act, 2015, P.L. 113-235 (113th Cong. 2014); Consolidated
Appropriations Act, 2016, P.L. 114-113 (114th Cong. 2015); Consolidated Appropriations Act, 2017, P.L. 115-31
(115th Cong. 2017); Consolidated Appropriations Act, 2018, P.L. 115-141 (115th Cong. 2018); Consolidated
Appropriations Act, 2019, P.L. 116-6 (116th Cong. 2019); Consolidated Appropriations Act, 2020, P.L. 116-93 (116th
Cong. 2019); Consolidated Appropriations Act, 2021, P.L. 116-260 (116th Cong. 2020); and Consolidated

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On its face, the appropriations rider bars DOJ from taking legal action against the states directly
in order to prevent them from promulgating or enforcing medical marijuana laws.160 In addition,
federal courts have interpreted the rider to prohibit certain federal prosecutions of private
individuals or organizations that produce, distribute, or possess marijuana in accordance with
state medical marijuana laws. In the 2016 case United States v. McIntosh, the U.S. Court of
Appeals for the Ninth Circuit held that the rider
prohibits the federal government only from preventing the implementation of those specific
rules of state law that authorize the use, distribution, possession, or cultivation of medical
marijuana. DOJ does not prevent the implementation of [such rules] when it prosecutes
individuals who engage in conduct unauthorized under state medical marijuana laws.
Individuals who do not strictly comply with all state-law conditions regarding the use,
distribution, possession, and cultivation of medical marijuana have engaged in conduct that
is unauthorized, and prosecuting such individuals does not violate [the rider].161

The Ninth Circuit has issued several decisions allowing federal prosecution of individuals who
did not strictly comply with state medical marijuana laws, notwithstanding the appropriations
rider, and several district courts have followed that holding

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AR44782. Public record. Not legal advice.