MPEP § 2301 — Interference Proceedings (Annotated Rules)

§2301 Interference Proceedings

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

This page consolidates and annotates all enforceable requirements under MPEP § 2301, 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.

Interference Proceedings

This section addresses Interference Proceedings. Primary authority: 35 U.S.C. 135(a), 35 U.S.C. 102(g)(1), and 37 CFR 41.202. Contains: 1 requirement, 5 permissions, and 8 other statements.

Key Rules

Topic

PTAB Jurisdiction

7 rules
StatutoryInformativeAlways
[mpep-2301-b643e7711dc08b481f4c1ff4]
Examiner Refers Suggested Interference to Board
Note:
The examiner refers a suggested interference under 37 CFR 41.202 to the Board for declaration and administration.

An interference is a contest under pre-AIA 35 U.S.C. 135(a) between an application and either another application or a patent. An interference is declared to assist the Director of the United States Patent and Trademark Office in determining priority, that is, which party first invented the commonly claimed invention within the meaning of pre-AIA 35 U.S.C. 102(g)(1). See MPEP § 2301.03. Once an interference has been suggested under 37 CFR 41.202, the examiner refers the suggested interference to the Board. An administrative patent judge declares the interference, which is then administered at the Board. A panel of Board members enters final judgment on questions of priority and patentability arising in an interference.

Jump to MPEP Source · 37 CFR 41.202PTAB JurisdictionPTAB Contested Case ProceduresDetermining Whether Application Is AIA or Pre-AIA
StatutoryInformativeAlways
[mpep-2301-f500fb7cb73f7d01e51ad9cc]
Administrative Patent Judge Declares Interference
Note:
An administrative patent judge declares an interference, which is then administered at the Board to determine priority and patentability.

An interference is a contest under pre-AIA 35 U.S.C. 135(a) between an application and either another application or a patent. An interference is declared to assist the Director of the United States Patent and Trademark Office in determining priority, that is, which party first invented the commonly claimed invention within the meaning of pre-AIA 35 U.S.C. 102(g)(1). See MPEP § 2301.03. Once an interference has been suggested under 37 CFR 41.202, the examiner refers the suggested interference to the Board. An administrative patent judge declares the interference, which is then administered at the Board. A panel of Board members enters final judgment on questions of priority and patentability arising in an interference.

Jump to MPEP Source · 37 CFR 41.202PTAB JurisdictionPTAB Contested Case ProceduresDetermining Whether Application Is AIA or Pre-AIA
StatutoryInformativeAlways
[mpep-2301-13bb9f270d465e4d82cb12a1]
Examiner Action Halts Until Interference Ends
Note:
The examiner will not review the application again until any interference proceedings are concluded.

Once the interference is declared, the examiner generally will not treat the application again until the interference has been terminated. Occasionally, however, the Board may refer a matter to the examiner or may consult with the examiner on an issue. Given the very tight deadlines in an interference, any action on a consultation or referral from the Board must occur with special dispatch.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryPermittedAlways
[mpep-2301-5ca72babad877be9c062a3dd]
Board May Refer Matters to Examiner During Interference
Note:
The Board can consult with the examiner on issues even after an interference has been declared, ensuring timely action within tight deadlines.

Once the interference is declared, the examiner generally will not treat the application again until the interference has been terminated. Occasionally, however, the Board may refer a matter to the examiner or may consult with the examiner on an issue. Given the very tight deadlines in an interference, any action on a consultation or referral from the Board must occur with special dispatch.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryRequiredAlways
[mpep-2301-96247085d42517b5d9ad5f67]
Examiner Action on Board Consultations Must Be Prompt
Note:
When the Board consults with or refers matters to the examiner during an interference, the examiner must respond promptly due to tight deadlines.

Once the interference is declared, the examiner generally will not treat the application again until the interference has been terminated. Occasionally, however, the Board may refer a matter to the examiner or may consult with the examiner on an issue. Given the very tight deadlines in an interference, any action on a consultation or referral from the Board must occur with special dispatch.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryPermittedAlways
[mpep-2301-0f0e8b299ac98c24b3db0b17]
Board May Recommend Examiner Action
Note:
The Board may suggest actions for the examiner to take in a case after interference proceedings are terminated.

The application returns to the examiner after the interference has been terminated. Depending on the nature of the judgment in the case, the examiner may need to take further action in the application. For instance, if there are remaining allowable claims, the application may need to be passed to issue. The Board may have entered a recommendation for further action by the examiner in the case. If the applicant has lost an issue in the interference, the applicant may be barred from taking action in the application or any subsequent application that would be inconsistent with that loss.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEstoppel After Judgment
StatutoryInformativeAlways
[mpep-2301-18c77a5320f35ec6d8c1ff34]
Examiner Must Consult IPS for Possible Interference
Note:
The examiner must immediately consult an Interference Practice Specialist once a possible interference is identified and complete examination before referring it to the Board.

Given the infrequency, cost, and complexity of interferences and derivation proceedings, it is important for the examiner to consult immediately with an Interference Practice Specialist (IPS) in the examiner’s Technology Center, see MPEP § 2302, once a possible interference is identified. It is also important to complete examination before the possible interference is referred to the Board. See MPEP § 2303. See MPEP § 2310 et seq. for discussion of derivation proceedings.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
Topic

Estoppel After Judgment

5 rules
StatutoryInformativeAlways
[mpep-2301-412f7e221322d71309b92b96]
Board Enters Final Judgment on Priority and Patentability in Interference
Note:
A panel of Board members makes the final decision on questions related to priority and patentability during an interference proceeding.

An interference is a contest under pre-AIA 35 U.S.C. 135(a) between an application and either another application or a patent. An interference is declared to assist the Director of the United States Patent and Trademark Office in determining priority, that is, which party first invented the commonly claimed invention within the meaning of pre-AIA 35 U.S.C. 102(g)(1). See MPEP § 2301.03. Once an interference has been suggested under 37 CFR 41.202, the examiner refers the suggested interference to the Board. An administrative patent judge declares the interference, which is then administered at the Board. A panel of Board members enters final judgment on questions of priority and patentability arising in an interference.

Jump to MPEP Source · 37 CFR 41.202Estoppel After JudgmentPTAB JurisdictionPTAB Contested Case Procedures
StatutoryInformativeAlways
[mpep-2301-9dedc610b07ccf4b45706d8e]
Application Returned to Examiner After Interference Termination
Note:
The application is returned to the examiner after an interference has been terminated, and the examiner may need to take further action based on the judgment in the case.

The application returns to the examiner after the interference has been terminated. Depending on the nature of the judgment in the case, the examiner may need to take further action in the application. For instance, if there are remaining allowable claims, the application may need to be passed to issue. The Board may have entered a recommendation for further action by the examiner in the case. If the applicant has lost an issue in the interference, the applicant may be barred from taking action in the application or any subsequent application that would be inconsistent with that loss.

Jump to MPEP SourceEstoppel After JudgmentPTAB JurisdictionPTAB Contested Case Procedures
StatutoryPermittedAlways
[mpep-2301-3b51f8f964e42b6f1cf654b2]
Judgment Nature Dictates Examiner Actions
Note:
The examiner must take further action in the application based on the nature of the judgment, such as passing the application to issue if there are remaining allowable claims.

The application returns to the examiner after the interference has been terminated. Depending on the nature of the judgment in the case, the examiner may need to take further action in the application. For instance, if there are remaining allowable claims, the application may need to be passed to issue. The Board may have entered a recommendation for further action by the examiner in the case. If the applicant has lost an issue in the interference, the applicant may be barred from taking action in the application or any subsequent application that would be inconsistent with that loss.

Jump to MPEP SourceEstoppel After JudgmentPTAB JurisdictionPTAB Contested Case Procedures
StatutoryPermittedAlways
[mpep-2301-8f4c13cc6d08dfdd1a0a94c8]
Application May Need to Issue After Interference
Note:
If there are remaining allowable claims after an interference, the application may proceed to issue.

The application returns to the examiner after the interference has been terminated. Depending on the nature of the judgment in the case, the examiner may need to take further action in the application. For instance, if there are remaining allowable claims, the application may need to be passed to issue. The Board may have entered a recommendation for further action by the examiner in the case. If the applicant has lost an issue in the interference, the applicant may be barred from taking action in the application or any subsequent application that would be inconsistent with that loss.

Jump to MPEP SourceEstoppel After JudgmentPTAB JurisdictionPTAB Contested Case Procedures
StatutoryPermittedAlways
[mpep-2301-5178a71e1c96d8e000e7a7f1]
Estoppel After Losing Interference
Note:
An applicant who loses an issue in interference is barred from taking inconsistent actions in the application or any subsequent applications.

The application returns to the examiner after the interference has been terminated. Depending on the nature of the judgment in the case, the examiner may need to take further action in the application. For instance, if there are remaining allowable claims, the application may need to be passed to issue. The Board may have entered a recommendation for further action by the examiner in the case. If the applicant has lost an issue in the interference, the applicant may be barred from taking action in the application or any subsequent application that would be inconsistent with that loss.

Jump to MPEP SourceEstoppel After JudgmentPTAB JurisdictionPTAB Contested Case Procedures
Topic

AIA vs Pre-AIA Practice

1 rules
StatutoryInformativeAlways
[mpep-2301-1d3002c3e8e21f5fa6531c82]
Contest Between Application and Patent
Note:
An interference is a contest under pre-AIA 35 U.S.C. 135(a) to determine priority between an application and another application or patent.

An interference is a contest under pre-AIA 35 U.S.C. 135(a) between an application and either another application or a patent. An interference is declared to assist the Director of the United States Patent and Trademark Office in determining priority, that is, which party first invented the commonly claimed invention within the meaning of pre-AIA 35 U.S.C. 102(g)(1). See MPEP § 2301.03. Once an interference has been suggested under 37 CFR 41.202, the examiner refers the suggested interference to the Board. An administrative patent judge declares the interference, which is then administered at the Board. A panel of Board members enters final judgment on questions of priority and patentability arising in an interference.

Jump to MPEP Source · 37 CFR 41.202AIA vs Pre-AIA PracticeDetermining Whether Application Is AIA or Pre-AIADetermining AIA vs Pre-AIA Applicability (MPEP 2159)
Topic

Determining Whether Application Is AIA or Pre-AIA

1 rules
StatutoryInformativeAlways
[mpep-2301-09d91302704839096c7a091a]
Interference to Determine Priority
Note:
The Director of the United States Patent and Trademark Office uses an interference to determine which party first invented a commonly claimed invention under pre-AIA 35 U.S.C. 102(g)(1).

An interference is a contest under pre-AIA 35 U.S.C. 135(a) between an application and either another application or a patent. An interference is declared to assist the Director of the United States Patent and Trademark Office in determining priority, that is, which party first invented the commonly claimed invention within the meaning of pre-AIA 35 U.S.C. 102(g)(1). See MPEP § 2301.03. Once an interference has been suggested under 37 CFR 41.202, the examiner refers the suggested interference to the Board. An administrative patent judge declares the interference, which is then administered at the Board. A panel of Board members enters final judgment on questions of priority and patentability arising in an interference.

Jump to MPEP Source · 37 CFR 41.202Determining Whether Application Is AIA or Pre-AIADetermining AIA vs Pre-AIA Applicability (MPEP 2159)AIA vs Pre-AIA Practice

Citations

Primary topicCitation
AIA vs Pre-AIA Practice
Determining Whether Application Is AIA or Pre-AIA
Estoppel After Judgment
PTAB Jurisdiction
35 U.S.C. § 102(g)(1)
AIA vs Pre-AIA Practice
Determining Whether Application Is AIA or Pre-AIA
Estoppel After Judgment
PTAB Jurisdiction
35 U.S.C. § 135(a)
AIA vs Pre-AIA Practice
Determining Whether Application Is AIA or Pre-AIA
Estoppel After Judgment
PTAB Jurisdiction
37 CFR § 41.202
AIA vs Pre-AIA Practice
Determining Whether Application Is AIA or Pre-AIA
Estoppel After Judgment
PTAB Jurisdiction
MPEP § 2301.03
PTAB JurisdictionMPEP § 2302
PTAB JurisdictionMPEP § 2303
PTAB JurisdictionMPEP § 2310

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