MPEP § 2808 — Time for Requesting Supplemental Examination (Annotated Rules)

§2808 Time for Requesting Supplemental Examination

USPTO MPEP version: BlueIron's Update: 2026-01-17

This page consolidates and annotates all enforceable requirements under MPEP § 2808, 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 Requesting Supplemental Examination

This section addresses Time for Requesting Supplemental Examination. Primary authority: 35 U.S.C. 286), 35 U.S.C. 286, and 35 U.S.C. 154. Contains: 1 prohibition, 1 guidance statement, 4 permissions, and 1 other statement.

Key Rules

Topic

Statutory Authority for Examination

4 rules
StatutoryPermittedAlways
[mpep-2808-cbd42df71f6331661ed9ea37]
Patent Owner Can Request Supplemental Examination Any Time During Patent Enforceability
Note:
A patent owner may file a request for supplemental examination at any time during the period of enforceability of a patent, which is generally six years after expiration but can be extended if litigation is pending.

Under 37 CFR 1.601(c), a patent owner may, at any time during the period of enforceability of a patent, file a request for supplemental examination. This period was set by rule, because the Office believes that Congress could not have intended the Office to expend resources on the supplemental examination of a patent which cannot be enforced. The enforceability period is generally determined by adding six years to the date on which the patent expires, but the period may be extended if litigation is pending. Specifically, if litigation is instituted within the statute of limitations (see 35 U.S.C. 286), requests for supplemental examination may be filed after the statute of limitations has expired, as long as the patent is still enforceable against someone.

Jump to MPEP Source · 37 CFR 1.601(c)Statutory Authority for ExaminationExamination ProceduresSupplemental Examination Request
StatutoryProhibitedAlways
[mpep-2808-43999107bc85f81ebe0f33e3]
Period for Requesting Supplemental Examination Determined by Rule
Note:
The Office sets the period for requesting supplemental examination based on the belief that Congress did not intend to allocate resources for examining patents that cannot be enforced.

Under 37 CFR 1.601(c), a patent owner may, at any time during the period of enforceability of a patent, file a request for supplemental examination. This period was set by rule, because the Office believes that Congress could not have intended the Office to expend resources on the supplemental examination of a patent which cannot be enforced. The enforceability period is generally determined by adding six years to the date on which the patent expires, but the period may be extended if litigation is pending. Specifically, if litigation is instituted within the statute of limitations (see 35 U.S.C. 286), requests for supplemental examination may be filed after the statute of limitations has expired, as long as the patent is still enforceable against someone.

Jump to MPEP Source · 37 CFR 1.601(c)Statutory Authority for ExaminationExamination ProceduresSupplemental Examination
StatutoryPermittedAlways
[mpep-2808-4bba4f25923391e4cc6064da]
Enforceability Period Extended for Pending Litigation
Note:
The enforceability period is generally six years after patent expiration but can be extended if litigation is pending.

Under 37 CFR 1.601(c), a patent owner may, at any time during the period of enforceability of a patent, file a request for supplemental examination. This period was set by rule, because the Office believes that Congress could not have intended the Office to expend resources on the supplemental examination of a patent which cannot be enforced. The enforceability period is generally determined by adding six years to the date on which the patent expires, but the period may be extended if litigation is pending. Specifically, if litigation is instituted within the statute of limitations (see 35 U.S.C. 286), requests for supplemental examination may be filed after the statute of limitations has expired, as long as the patent is still enforceable against someone.

Jump to MPEP Source · 37 CFR 1.601(c)Statutory Authority for ExaminationExamination ProceduresSupplemental Examination Request
StatutoryPermittedAlways
[mpep-2808-0780f190c8977c94d549b59a]
Supplemental Examination After Statute of Limitations
Note:
Requests for supplemental examination can be filed after the statute of limitations if litigation is pending and the patent remains enforceable.

Under 37 CFR 1.601(c), a patent owner may, at any time during the period of enforceability of a patent, file a request for supplemental examination. This period was set by rule, because the Office believes that Congress could not have intended the Office to expend resources on the supplemental examination of a patent which cannot be enforced. The enforceability period is generally determined by adding six years to the date on which the patent expires, but the period may be extended if litigation is pending. Specifically, if litigation is instituted within the statute of limitations (see 35 U.S.C. 286), requests for supplemental examination may be filed after the statute of limitations has expired, as long as the patent is still enforceable against someone.

Jump to MPEP Source · 37 CFR 1.601(c)Statutory Authority for ExaminationExamination ProceduresLate Payment and Reinstatement
Topic

Determining Expiration Date

3 rules
StatutoryInformativeAlways
[mpep-2808-69a86854b943f0ae9c1007ef]
Patent Owner Determines Expiration Date for Supplemental Examination
Note:
The patent owner is responsible for determining the expiration date of a patent undergoing supplemental examination, considering various factors such as term, maintenance fees, and extensions.

It is the responsibility of the patent owner to determine the expiration date of the patent for which supplemental examination is requested. For example, the expiration date of a utility patent may be determined by taking into account the term of the patent, whether maintenance fees have been paid for the patent, whether any disclaimer was filed as to the patent to shorten its term, any patent term extensions or adjustments for delays within the Office under 35 U.S.C. 154 (see MPEP § 2710, et seq.), and any patent term extensions available under 35 U.S.C. 156 for premarket regulatory review (see MPEP § 2750 et seq.). Any other relevant information should also be taken into account.

Jump to MPEP Source · 37 CFR 1.601Determining Expiration DatePatent Term ExpirationPatent Term
StatutoryPermittedAlways
[mpep-2808-21c485bd9cfbb9e5bf7bc09f]
How to Determine Patent Expiration Date
Note:
This rule outlines the factors that must be considered to determine the expiration date of a utility patent, including term, maintenance fees, disclaimers, and extensions.

It is the responsibility of the patent owner to determine the expiration date of the patent for which supplemental examination is requested. For example, the expiration date of a utility patent may be determined by taking into account the term of the patent, whether maintenance fees have been paid for the patent, whether any disclaimer was filed as to the patent to shorten its term, any patent term extensions or adjustments for delays within the Office under 35 U.S.C. 154 (see MPEP § 2710, et seq.), and any patent term extensions available under 35 U.S.C. 156 for premarket regulatory review (see MPEP § 2750 et seq.). Any other relevant information should also be taken into account.

Jump to MPEP Source · 37 CFR 1.601Determining Expiration DatePatent Term ExpirationPatent Term
StatutoryRecommendedAlways
[mpep-2808-1d5aa8ff8a9b1cb6af34c669]
Expiration Date Determination for Supplemental Examination
Note:
The patent owner must determine the expiration date of a patent for supplemental examination, considering various factors like term, maintenance fees, and extensions.

It is the responsibility of the patent owner to determine the expiration date of the patent for which supplemental examination is requested. For example, the expiration date of a utility patent may be determined by taking into account the term of the patent, whether maintenance fees have been paid for the patent, whether any disclaimer was filed as to the patent to shorten its term, any patent term extensions or adjustments for delays within the Office under 35 U.S.C. 154 (see MPEP § 2710, et seq.), and any patent term extensions available under 35 U.S.C. 156 for premarket regulatory review (see MPEP § 2750 et seq.). Any other relevant information should also be taken into account.

Jump to MPEP Source · 37 CFR 1.601Determining Expiration DatePatent Term ExpirationPatent Term

Citations

Primary topicCitation
Determining Expiration Date35 U.S.C. § 154
Determining Expiration Date35 U.S.C. § 156
Statutory Authority for Examination35 U.S.C. § 286
Statutory Authority for Examination37 CFR § 1.601(c)
Determining Expiration DateMPEP § 2710
Determining Expiration DateMPEP § 2750

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: 2026-01-17