# Selected Issues in Tax Reform: Federal Subsidies for Municipal Bond Interest

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URL: https://www.frixlaw.com/law-library/documents/crs%3AIF12969

## Record

- **Collection:** Congressional research report
- **Document type:** In Focus
- **Published:** April 16, 2025
- **Citation:** IF12969

## Text

April 16, 2025

Selected Issues in Tax Reform: Federal Subsidies for Municipal
Bond Interest
The federal tax code includes subsidies for interest income
earned on state and local (municipal) bonds. Municipal
governments issue bonds to investors to finance
investments in exchange for interest payments and the
eventual repayment of principal (the amount borrowed).
Federal bond subsidies have been subject to sustained
legislative interest, including changes enacted by P.L. 11597 (often referred to as the Tax Cuts and Jobs Act, or
TCJA) and the Infrastructure Investment and Jobs Act of
2021 (IIJA; P.L. 117-58). This In Focus summarizes the
subsidies provided under current federal law, discusses
changes enacted in recent Congresses, and briefly examines
relevant policy issues.

Summary and Legislative Background
The federal government subsidizes state and local debt
through three policies: (1) all interest income earned from
public purpose bonds is excluded from federal income
taxation; (2) interest income earned from qualified private
activity bonds (PABs) is excluded from federal regular
income taxation; and (3) a tax credit may be claimed on
interest income in lieu of the exclusion in some cases,
though authority to issue new tax credit bonds has expired.
Table 1. Projected Tax Expenditures on Federal Bond
Subsidies, FY2024-FY2028
Billions of dollars
Reduced
Revenues

Increased
Outlays

Total

Tax-Exempt
Bonds

131.0

—

131.0

Qualified
PABs

49.9

—

49.9

Tax Credit
Bonds

1.5

13.3

14.8

Source: Joint Committee on Taxation, Estimates of Federal Tax
Expenditures for Fiscal Years 2024-2028, JCX-48-24, December 2024.

Table 1 shows Joint Committee on Taxation (JCT)
estimates of the budgetary effects of federal bond subsidies
from FY2024 to FY2028. The federal bond subsidies are
projected to provide a total of $196 billion in benefits over
five years. That annual subsidy represents about 1% of the
current municipal debt stock: the Federal Reserve estimated
that state and local governments had $3.3 trillion in debt
issuances outstanding in the last quarter of 2024.
Tax-Exempt Bonds
Bonds are considered to be for a public purpose if they
satisfy either of two criteria: (1) less than 10% of the

proceeds are used directly or indirectly by a
nongovernmental entity; or (2) less than 10% of the bond
proceeds are secured directly or indirectly by property used
in a trade or business. Bonds that satisfy either test are
called “governmental” bonds and can be issued without
federal restriction. The federal government subsidizes the
cost of governmental bonds by excluding interest income
earned by investors on those bonds from federal income
taxation. The exclusion lowers the cost of debt for state and
local governments by allowing them to borrow at lower
interest rates than would otherwise apply if the interest
income were taxable.
The lower interest rates arise because in most cases
investors will be indifferent between taxable and taxexempt bonds of equivalent risk if their after-tax return is
identical. For example, consider a taxpayer in the 37% tax
bracket who seeks to invest in a taxable bond with a 10%
interest rate or a tax-exempt bond with a 6.3% interest rate.
The taxability of the bond with the 10% interest rate makes
the investor’s after-tax income identical to that of the taxexempt bond with a 6.3% interest rate. Thus, state and local
governments could raise capital from investors at an interest
cost 3.7 percentage points lower than a borrower issuing
taxable debt.
The direct cost to the federal government of tax-exempt
bonds is the individual and corporate income tax revenue
forgone. In the example above, a taxable bond with a 10%
interest rate would have generated federal tax revenue equal
to 3.7% (37% x 10%) of the bond’s principal value
annually.
Some bonds, called refunding bonds, are issued to replace
outstanding bonds with less favorable terms. There are two
types of refunding bonds: current refunding bonds, which
are redeemed within 90 days of the refunding bond issue
date, and advance refunding bonds, which are issued in
such a way that both the original and refunding bonds are
outstanding longer than 90 days. Only current refunding
bonds are eligible for a federal tax subsidy, as P.L. 115-97
repealed the ability to issue tax-exempt advance refunding
bonds. Refunding bonds may be issued for public or private
purposes.
Qualified Private Activity Bonds
Bonds that fail both public purpose tests are termed privateactivity bonds (PABs) because they provide significant
benefits to private individuals or businesses. These projects
are generally ineligible for tax-exempt financing. However,
activities that fail each test but that Congress considers to
provide both public and private benefits are categorized as
qualified and can be financed with qualified PABs, which

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Selected Issues in Tax Reform: Federal Subsidies for Municipal Bond Interest

are tax exempt. Only qualified activities included in the
federal code can be financed with tax-exempt PABs. About
30 types of issuances are eligible for the qualified PAB
subsidy. The IIJA created two new qualified PAB
categories (for certain broadband projects and carbon
capture facilities) and increased an overall limitation on the
issuances available for certain highway and surface transfer
facility bonds.
Some qualified PABs are also subject to an annual, statespecific issuance cap intended to limit the benefits provided
through the subsidy. The value of bonds issued for these
activities by all governmental units in a state is limited to
the greater of $130 per resident or $388.8 million in 2025.
Tax Credit Bonds
Tax credit bonds (TCBs) were created as an alternative to
tax-exempt bonds. TCBs provide a tax credit or direct
payment proportional to the bond’s face value in lieu of the
tax exemption. Unlike tax-exempt bonds, the value of the
credit is not dependent on the investor’s marginal income
tax rate. The relative appeal of TCBs and tax-exempt bonds
varies with bond interest rates, tax status of the investor,
and underlying economic conditions.
All authority to issue tax credit bonds was repealed by P.L.
115-97, though most TCBs in the tax code were not eligible
for new issuances prior to the law’s enactment. Outstanding
TCBs are still held by the public and thus still receive the
federal subsidy. Most TCBs were designated for a specific
purpose, including public school construction and
renovation, clean renewable energy projects, and
refinancing outstanding government debt in regions
affected by natural disasters.

Policy Considerations
Certain goods and services provided by state or local
governments benefit both residents, who pay municipal
taxes, and nonresidents, who pay minimal if any municipal
taxes. State and local taxpayers may be unwilling to provide
these services to nonresidents without compensation, which
could cause the services to be underprovided relative to
their public benefits. In theory, such spillover effects could
justify some federal financing for state and local projects.
Subsidizing debt issuance specifically has the benefit of
harmonizing the timing of the subsidy with the period over
which bond-financed facilities provide services. State and
local taxpayers lay claim to the benefits from these facilities
through residency and relinquish benefit claim when they
move. State or local officials may therefore prefer to spread
the timing of the payments more evenly with the provision
of services, precisely the function served by long-term bond
financing.
State and local governments typically must plan their
budgets one to two years in advance, and often are required
to balance some or all of their incoming and outgoing
payments. Unforeseen circumstances can undermine such
plans and cause a revenue shortfall, which must be financed
with short-term borrowing. Timing issues may also create
the necessity to borrow within an otherwise balanced fiscal
year. Finally, temporarily high interest rates that prevail at

the time bonds are issued may induce short-term borrowing
in anticipation of a drop in rates. Federal subsidies reduce
the costs of these activities, though the economic rationale
behind the transfer of such costs from municipal taxpayers
to federal taxpayers is less clear.
Critics of the subsidies for municipal debt believe that they
represent a suboptimal allocation of federal resources, as
some observers believe that the subsidies for municipal debt
could be better used on some combination of direct federal
investment in municipal infrastructure, other federal
programs, or deficit reduction. Moreover, since the amount
of capital investors are willing to loan is limited, offering
subsidies for municipal debt may increase the interest costs
for other types of debt issuances, including for federal
borrowing and private financing.
The bond subsidies also affect the distribution of the federal
tax system. Benefits from tax-exempt bonds and qualified
PABs are directly proportional to the investor’s marginal
tax rate, meaning that higher-income taxpayers benefit
more from them than do lower-income taxpayers. Higherincome taxpayers also tend to have more disposable capital
to loan to municipal governments, making them more likely
to receive such benefits.

Recent Reform Proposals
The Congressional Budget Office published an option in its
December 2024 Options for Reducing the Deficit report that
would eliminate the tax exemption for new qualified PABs.
The JCT estimated that proposal would increase revenues
by about $43 billion over the FY2025-FY2034 period.
An early version of P.L. 115-97 considered in the House
prior to its enactment included language that would have
(1) repealed all new issuance authority of qualified PABs;
and (2) amended the definition of tax-exempt bonds so that
issuances for the construction of professional sports
stadiums did not qualify for the exemption. P.L. 115-97 as
enacted did not include that language.
Recently introduced legislation that would modify federal
bond subsidies has included, but is not limited to

• legislation that would create new qualified PAB
categories, including for spaceports (S. 3823 and H.R.
7470 in the 118th Congress) and for replacement of lead
service lines in public water systems (S. 726 and H.R.
6985 in the 118th);

• legislation that would expand bond subsidies, including
expanded use for tribal governments (S. 5048 in the
117th), reinstatement of advance refunding bonds (S.
1453 in the 118th), and reinstatement of TCBs for certain
infrastructure projects (S. 1403 in the 117th); and

• legislation that would restrict bond subsidies, including
repealing bond subsidies for sports stadiums (S. 392 and
H.R. 993 in the 118th), and denial of bond issuances for
certain governments (H.R. 1879 in the 119th).
Grant A. Driessen, Acting Section Research Manager

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IF12969

Selected Issues in Tax Reform: Federal Subsidies for Municipal Bond Interest

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https://crsreports.congress.gov | IF12969 · VERSION 1 · NEW

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AIF12969. Public record. Not legal advice.
