MPEP § 2204 — Time for Filing Prior Art or Section 301 Written Statements (Annotated Rules)

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

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 2204, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Time for Filing Prior Art or Section 301 Written Statements

This section addresses Time for Filing Prior Art or Section 301 Written Statements. Primary authority: 35 U.S.C. 301, 35 U.S.C. 286), and 35 U.S.C. 286. Contains: 1 requirement, 2 permissions, and 1 other statement.

Key Rules

Topic

Request Content Requirements

3 rules
StatutoryPermittedAlways
[mpep-2204-946418c68f7db34469ce67ca]
Submissions During Patent Enforceability Period
Note:
Submissions can be filed at any time during the patent's enforceability period, which includes its term plus a 6-year statute of limitations for infringement actions.

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.

Jump to MPEP Source · 37 CFR 1.501(a))Request Content RequirementsRequest by Patent OwnerThird Party Requester
StatutoryInformativeAlways
[mpep-2204-7ef37c2ade75cd9cb590766a]
Period of Enforceability for Patent Infringement Actions
Note:
The period during which a patent can be enforced includes the patent term plus six years from when infringement is discovered.

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.

Jump to MPEP Source · 37 CFR 1.501(a))Request Content RequirementsRequest by Patent OwnerThird Party Requester
StatutoryPermittedAlways
[mpep-2204-09ee067fe829df4774c5cd0f]
Submissions Allowed After Statute If Litigation Instituted
Note:
Patent submissions may be filed after the statute of limitations if litigation is initiated within that period and the patent remains enforceable.

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.

Jump to MPEP Source · 37 CFR 1.501(a))Request Content RequirementsRequest by Patent OwnerThird Party Requester
Topic

Request by Patent Owner

1 rules
StatutoryRequiredAlways
[mpep-2204-f012340c1cecba3cde2c170b]
Submissions After Reexamination Order
Note:
Patent owner submissions after a reexamination order can only be entered into the file if made by the patent owner or under specific conditions.

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.

Jump to MPEP Source · 37 CFR 1.501(a))Request by Patent OwnerThird Party RequesterReexamination Filing Fee

Citations

Primary topicCitation
Request Content Requirements
Request by Patent Owner
35 U.S.C. § 286
Request Content Requirements
Request by Patent Owner
35 U.S.C. § 301
Request Content Requirements
Request by Patent Owner
37 CFR § 1.501(a)
Request Content Requirements
Request by Patent Owner
37 CFR § 1.501(c)
Request Content Requirements
Request by Patent Owner
37 CFR § 1.510
Request Content Requirements
Request by Patent Owner
37 CFR § 1.535
Request Content Requirements
Request by Patent Owner
37 CFR § 1.948

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31