# MPEP § 2204: Time for Filing Prior Art or Section 301 Written Statements

> Federal · Agency guidance · In force

URL: https://www.frixlaw.com/law-library/statutes/MPEP_S2204

## Section

- **Citation:** MPEP § 2204
- **Heading:** Time for Filing Prior Art or Section 301 Written Statements
- **Jurisdiction:** Federal
- **Kind:** Agency guidance
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** USPTO MPEP / Chapter 2200 - Citation of Prior Art and Ex Parte Reexamination of Patents / MPEP § 2204

## Text

Submissions may be filed “at any time” under
35 U.S.C.
301
. However, this period has been defined by rule (
37 CFR 1.501(a)
) to
be “any time during the period of enforceability of a patent.” The period of enforceability
is generally the length of the term of the patent plus the 6 years under the statute of
limitations for bringing an infringement action (
35 U.S.C. 286
). In addition, if
litigation is instituted within the period of the statute of limitations, submissions may
be filed after the statute of limitations has expired, as long as the patent is still
enforceable against someone. While submission under
35 U.S.C.
301
may be filed at any time during the period of enforceability of
the patent, submissions filed after the date of any order to reexamine will not be entered
into the patent file until the pending reexamination proceeding has been concluded
(
37 CFR
1.501(c)
), unless the submissions are submitted (A) by the patent
owner, (B) by an
ex parte
reexamination requester who also submits the
appropriate fee and other documents required under
37 CFR 1.510
, (C) in an
ex
parte
third party requester’s reply under
37 CFR 1.535
, or (D) as an enterable
submission pursuant to
37
CFR 1.948
in an
inter partes
reexamination
proceeding.
The purpose of this rule is to prevent harassment of the patent owner due
to frequent submissions of prior art citations during reexamination proceedings.
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## Nearby sections

- [MPEP § 2201 Introduction](https://www.frixlaw.com/law-library/statutes/MPEP_S2201.md)
- [MPEP § 2202 Citation of Prior Art and Written Statements](https://www.frixlaw.com/law-library/statutes/MPEP_S2202.md)
- [MPEP § 2203 Persons Who May Cite Prior Art or Written Statements](https://www.frixlaw.com/law-library/statutes/MPEP_S2203.md)
- [MPEP § 2204 Time for Filing Prior Art or Section 301 Written Statements](https://www.frixlaw.com/law-library/statutes/MPEP_S2204.md)
- [MPEP § 2205 Content of Prior Art or Section 301 Written Statements](https://www.frixlaw.com/law-library/statutes/MPEP_S2205.md)
- [MPEP § 2206 Submission and Handling of Prior Art or Section 301 Written Statements](https://www.frixlaw.com/law-library/statutes/MPEP_S2206.md)
- [MPEP § 2207 Entry of Court Decision in Patent File](https://www.frixlaw.com/law-library/statutes/MPEP_S2207.md)
- [MPEP § 2208 Service of Prior Art or Section 301 Written Statements on Patent Owner](https://www.frixlaw.com/law-library/statutes/MPEP_S2208.md)
- [MPEP § 2209 Ex Parte Reexamination](https://www.frixlaw.com/law-library/statutes/MPEP_S2209.md)
- [MPEP § 2210 Request for Ex Parte Reexamination under 35 U.S.C. 302](https://www.frixlaw.com/law-library/statutes/MPEP_S2210.md)
- [MPEP § 2211 Time for Requesting Ex Parte Reexamination under 35 U.S.C. 302](https://www.frixlaw.com/law-library/statutes/MPEP_S2211.md)
- [MPEP § 2212 Persons Who May File a Request for Ex Parte Reexamination under 35 U.S.C. 302](https://www.frixlaw.com/law-library/statutes/MPEP_S2212.md)
- [MPEP § 2212.01 Inquiries from Persons Other Than the Patent Owner](https://www.frixlaw.com/law-library/statutes/MPEP_S2212.01.md)
- [MPEP § 2213 Representative of Requester](https://www.frixlaw.com/law-library/statutes/MPEP_S2213.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/MPEP_S2204. Check the current official text before relying on it. Not legal advice.