MPEP § 2201 — Introduction (Annotated Rules)

§2201 Introduction

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

This page consolidates and annotates all enforceable requirements under MPEP § 2201, 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.

Introduction

This section addresses Introduction. Primary authority: 35 U.S.C. 302, 35 U.S.C. 257, and 35 U.S.C. 101. Contains: 5 permissions and 9 other statements.

Key Rules

Topic

AIA Effective Dates

9 rules
StatutoryInformativeAlways
[mpep-2201-9288598985e2258fe5714a3c]
Guide for Processing Prior Art Citations and Ex Parte Reexamination Requests
Note:
This guide assists U.S. Patent and Trademark Office personnel in processing prior art citations and handling ex parte reexamination proceedings, including formal requirements for filing such documents.

This chapter is intended to primarily be a guide for U.S. Patent and Trademark Office (Office) personnel on the processing of prior art citations and ex parte reexamination requests under 35 U.S.C. 302, as well as handling ex parte reexamination proceedings. Second, it serves as a guide to the formal requirements for filing such documents in the Office. It is noted that all citations in this chapter to 35 U.S.C. discussing the first-to-invent prior art regime (as opposed to the first-inventor-to-file prior art regime) are to the relevant statute in effect prior to March 16, 2013.

Jump to MPEP SourceAIA Effective DatesRequest Content RequirementsAIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2201-c64758bdcc0647e36ffa5d0f]
Inter Partes Reexamination Process Changed by AIA
Note:
The American Inventors Protection Act of 1999 provided an optional inter partes reexamination procedure, but the Leahy-Smith America Invents Act replaced it with an inter partes review process on September 16, 2012.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceAIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2201-652adba0c0982bb690564a9d]
Optional Inter Partes Reexamination Procedures
Note:
The rule outlines the procedures for optional inter partes reexaminations filed before September 16, 2012.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceAIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2201-59f1c0b3775be6613ea1967f]
AIA Replaces Inter Partes Reexamination With Review Process
Note:
The Leahy-Smith America Invents Act replaced the inter partes reexamination process with an inter partes review process on September 16, 2012.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceAIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2201-f2728f88f2682ed35548516a]
Provisions for Inter Partes Reexaminations Filed Before September 16, 2012
Note:
The rules for inter partes reexaminations filed before September 16, 2012, continue to apply as they were prior to the AIA's effective date.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceAIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
MPEP GuidancePermittedAlways
[mpep-2201-dc688ee42a8841dff74b95a7]
Statements of Patent Owner Regarding Claim Scope Required in Proceedings
Note:
The AIA requires patent owners to provide statements regarding the scope of their claims in federal court or USPTO proceedings, which can be cited and considered in ex parte reexamination, inter partes review, and post grant review.

On September 16, 2012, the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted. The AIA expanded the scope of information that any party may cite in a patent file to include written statements of a patent owner filed in a proceeding before a federal court or the United States Patent and Trademark Office (Office) regarding the scope of any claim of the patent, and provides for how such information may be considered in ex parte reexamination, inter partes review, and post grant review. The AIA also provided for an estoppel that may attach with respect to the filing of an ex parte reexamination request subsequent to a final written decision in an inter partes review or post grant review proceeding.

Jump to MPEP SourceAIA Effective DatesInter Partes Review (IPR)Request by Patent Owner
MPEP GuidanceInformativeAlways
[mpep-2201-0c49e21dfb56e94cff559567]
Reexamination Uses Examining Prior Art Regime
Note:
Patent reexaminations generally follow the prior art regime of the original application, unless specific conditions are met.

The AIA also provided for a first-inventor-to-file prior art regime to replace the first-to-invent prior art regime, with respect to prior art available to be applied to claims. The prior art regime under which the application for the patent was examined (the first-inventor-to-file prior art regime, or the first-to-invent prior art regime) will generally be applied in the reexamination of the patent. However, there are rare exceptions. For example, a situation may arise in which a benefit claim to an application filed before March 16, 2013, is added in a reexamination proceeding based on an AIA patent. If all of the claims that have ever been presented in the reexamination proceeding and the underlying patent are fully supported by the prior application filed before March 16, 2013, and the application which resulted in the patent subject to the reexamination proceeding did not claim, directly or indirectly, the benefit of an application filed in the United States that presented at any time a claim that had an effective filing date on or after March 16, 2013, then the reexamination proceeding would be examined under the pre-AIA, first to invent, provisions.

Jump to MPEP SourceAIA Effective DatesDetermining Whether Application Is AIA or Pre-AIAAIA Overview and Effective Dates
MPEP GuidancePermittedAlways
[mpep-2201-62b7a23b8af2518cb1344fb2]
Pre-AIA Benefit Claim in AIA Reexamination
Note:
This rule allows a pre-AIA application benefit claim to be added in an AIA patent reexamination if all claims are supported by the original pre-AIA application and no post-2013 benefits were claimed.

The AIA also provided for a first-inventor-to-file prior art regime to replace the first-to-invent prior art regime, with respect to prior art available to be applied to claims. The prior art regime under which the application for the patent was examined (the first-inventor-to-file prior art regime, or the first-to-invent prior art regime) will generally be applied in the reexamination of the patent. However, there are rare exceptions. For example, a situation may arise in which a benefit claim to an application filed before March 16, 2013, is added in a reexamination proceeding based on an AIA patent. If all of the claims that have ever been presented in the reexamination proceeding and the underlying patent are fully supported by the prior application filed before March 16, 2013, and the application which resulted in the patent subject to the reexamination proceeding did not claim, directly or indirectly, the benefit of an application filed in the United States that presented at any time a claim that had an effective filing date on or after March 16, 2013, then the reexamination proceeding would be examined under the pre-AIA, first to invent, provisions.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
MPEP GuidanceInformativeAlways
[mpep-2201-5a8685eca2d1982aebb3fac7]
Reexamination Proceeding Examined Under Pre-AIA Provisions If Claims Fully Supported by Prior Application Filed Before March 16, 2013
Note:
If all claims in the reexamination and underlying patent are supported by a prior application filed before March 16, 2013, and no claim has an effective filing date on or after that date, the proceeding will be examined under pre-AIA first-to-invent provisions.

The AIA also provided for a first-inventor-to-file prior art regime to replace the first-to-invent prior art regime, with respect to prior art available to be applied to claims. The prior art regime under which the application for the patent was examined (the first-inventor-to-file prior art regime, or the first-to-invent prior art regime) will generally be applied in the reexamination of the patent. However, there are rare exceptions. For example, a situation may arise in which a benefit claim to an application filed before March 16, 2013, is added in a reexamination proceeding based on an AIA patent. If all of the claims that have ever been presented in the reexamination proceeding and the underlying patent are fully supported by the prior application filed before March 16, 2013, and the application which resulted in the patent subject to the reexamination proceeding did not claim, directly or indirectly, the benefit of an application filed in the United States that presented at any time a claim that had an effective filing date on or after March 16, 2013, then the reexamination proceeding would be examined under the pre-AIA, first to invent, provisions.

Jump to MPEP SourceAIA Effective DatesDetermining Whether Application Is AIA or Pre-AIAAIA Overview and Effective Dates
Topic

Statutory Authority for Examination

2 rules
StatutoryInformativeAlways
[mpep-2201-54e7fc3de1bbb1b73267f74b]
Supplemental Examination Proceeding for Patent Reexamination
Note:
Patent owners can request a supplemental examination to consider new information that may raise questions of patentability, leading to an ex parte reexamination if necessary.

Ex Parte Reexamination Proceedings Resulting from Supplemental Examination Proceedings: Section 12 of the AIA added new 35 U.S.C. 257, which provides for a proceeding titled “supplemental examination” that may be requested by the patent owner to consider, reconsider, or correct information believed to be relevant to the patent in accordance with requirements which have been established by the Office. The information that may be presented in a request for supplemental examination is not limited to patents and printed publications, and may include, for example, issues of patentability under 35 U.S.C. 101 and 35 U.S.C. 112. If the supplemental examination certificate, which is issued under 35 U.S.C. 257(a), states that a substantial new question of patentability is raised by one or more items of information in the request, ex parte reexamination of the patent will be ordered under 35 U.S.C. 257. See MPEP Chapter 2800 for guidance on the procedures for supplemental examination proceedings, and for procedures regarding the order and first Office action mailed in any ex parte reexamination proceeding ordered as a result of a supplemental examination proceeding.

Jump to MPEP SourceStatutory Authority for ExaminationEx Parte ReexaminationSupplemental Examination
StatutoryPermittedAlways
[mpep-2201-7bf02f81eb79676971c09b73]
Patent Owner Can Request Supplemental Examination to Consider Relevant Information
Note:
The patent owner may request a supplemental examination to reconsider or correct information relevant to the patent, which can lead to ex parte reexamination if new questions of patentability are raised.

Ex Parte Reexamination Proceedings Resulting from Supplemental Examination Proceedings: Section 12 of the AIA added new 35 U.S.C. 257, which provides for a proceeding titled “supplemental examination” that may be requested by the patent owner to consider, reconsider, or correct information believed to be relevant to the patent in accordance with requirements which have been established by the Office. The information that may be presented in a request for supplemental examination is not limited to patents and printed publications, and may include, for example, issues of patentability under 35 U.S.C. 101 and 35 U.S.C. 112. If the supplemental examination certificate, which is issued under 35 U.S.C. 257(a), states that a substantial new question of patentability is raised by one or more items of information in the request, ex parte reexamination of the patent will be ordered under 35 U.S.C. 257. See MPEP Chapter 2800 for guidance on the procedures for supplemental examination proceedings, and for procedures regarding the order and first Office action mailed in any ex parte reexamination proceeding ordered as a result of a supplemental examination proceeding.

Jump to MPEP SourceStatutory Authority for ExaminationAIA vs Pre-AIA PracticeSupplemental Examination
Topic

Conclusion of Ex Parte Reexamination

2 rules
MPEP GuidanceInformativeAlways
[mpep-2201-f1796f9d72a947798abb25a9]
New Sections for Prior Art Citation and Ex Parte Reexamination Available on July 1, 1981
Note:
The new sections 301-307 of title 35, United States Code, allow the citation of prior art patents or printed publications in patent files and ex parte reexamination of patents starting from July 1, 1981.

Statutory basis for citation of prior art patents or printed publications in patent files and ex parte reexamination of patents became available on July 1, 1981, as a result of new sections 301-307 of title 35, United States Code, which were added by Public Law 96-517, enacted on December 12, 1980. The rules of practice in patent cases relating to reexamination were initially promulgated on April 30, 1981, at 46 FR 24179-24180 and on May 29, 1981, at 46 FR 29176-29187.

Jump to MPEP SourceConclusion of Ex Parte ReexaminationEx Parte Reexamination
MPEP GuidancePermittedAlways
[mpep-2201-3e6e27e6e228dea077d89b3c]
Rules for Ex Parte Reexamination of Patents
Note:
The rules outline the procedures for challenging and reexamining patents, effective July 1, 1981.

Statutory basis for citation of prior art patents or printed publications in patent files and ex parte reexamination of patents became available on July 1, 1981, as a result of new sections 301-307 of title 35, United States Code, which were added by Public Law 96-517, enacted on December 12, 1980. The rules of practice in patent cases relating to reexamination were initially promulgated on April 30, 1981, at 46 FR 24179-24180 and on May 29, 1981, at 46 FR 29176-29187.

Jump to MPEP SourceConclusion of Ex Parte ReexaminationEx Parte Reexamination
Topic

SNQ Criteria

2 rules
MPEP GuidancePermittedAlways
[mpep-2201-78bd3e726f02e5fd40d23eba]
Expanded Substantial New Question Criteria for Ex Parte Reexamination
Note:
The rule expands the criteria for what qualifies as a substantial new question of patentability that can be used to initiate an ex parte reexamination and makes technical corrections to the statute.

The reexamination statute was amended on November 2, 2002, by Public Law 107-273, 116 Stat. 1758, 1899-1906 (2002) to expand the scope of what qualifies for a substantial new question of patentability upon which an ex parte reexamination may be based (see MPEP § 2242, subsection II.A), and made technical corrections to the statute. See the 21st Century Department of Justice Appropriations Authorization Act, TITLE III- INTELLECTUAL PROPERTY, Subtitle A – Patent and Trademark Office, Section 13105, of the “Patent and Trademark Office Authorization Act of 2002” – Enacted as part of Public Law 107-273 on November 2, 2002.

Jump to MPEP SourceSNQ CriteriaSubstantial New Question of PatentabilityEx Parte Reexamination
MPEP GuidanceInformativeAlways
[mpep-2201-780feb646ce30ce5997f607a]
Expansion of Substantial New Question Criteria for Ex Parte Reexamination
Note:
The rule expands the criteria for what qualifies as a substantial new question of patentability upon which an ex parte reexamination may be based.

The reexamination statute was amended on November 2, 2002, by Public Law 107-273, 116 Stat. 1758, 1899-1906 (2002) to expand the scope of what qualifies for a substantial new question of patentability upon which an ex parte reexamination may be based (see MPEP § 2242, subsection II.A), and made technical corrections to the statute. See the 21st Century Department of Justice Appropriations Authorization Act, TITLE III- INTELLECTUAL PROPERTY, Subtitle A – Patent and Trademark Office, Section 13105, of the “Patent and Trademark Office Authorization Act of 2002” – Enacted as part of Public Law 107-273 on November 2, 2002.

Jump to MPEP SourceSNQ CriteriaSubstantial New Question of PatentabilityEx Parte Reexamination
Topic

First Office Action on Merits

1 rules
StatutoryPermittedAlways
[mpep-2201-7c36005b210821fb47f9d63d]
Information for Supplemental Examination Not Limited to Patents and Publications
Note:
The information that can be included in a request for supplemental examination is not restricted to patents and printed publications, but may also include issues of patentability under sections 101 and 112.

Ex Parte Reexamination Proceedings Resulting from Supplemental Examination Proceedings: Section 12 of the AIA added new 35 U.S.C. 257, which provides for a proceeding titled “supplemental examination” that may be requested by the patent owner to consider, reconsider, or correct information believed to be relevant to the patent in accordance with requirements which have been established by the Office. The information that may be presented in a request for supplemental examination is not limited to patents and printed publications, and may include, for example, issues of patentability under 35 U.S.C. 101 and 35 U.S.C. 112. If the supplemental examination certificate, which is issued under 35 U.S.C. 257(a), states that a substantial new question of patentability is raised by one or more items of information in the request, ex parte reexamination of the patent will be ordered under 35 U.S.C. 257. See MPEP Chapter 2800 for guidance on the procedures for supplemental examination proceedings, and for procedures regarding the order and first Office action mailed in any ex parte reexamination proceeding ordered as a result of a supplemental examination proceeding.

Jump to MPEP SourceFirst Office Action on MeritsSubstantial New Question of PatentabilityStatutory Authority for Examination
Topic

First Action on Merits (FAOM)

1 rules
StatutoryInformativeAlways
[mpep-2201-ed89838ac9ad1310abffaa60]
Substantial New Question of Patentability Raised by Supplemental Exam
Note:
If a supplemental examination certificate states that a substantial new question of patentability is raised, ex parte reexamination will be ordered.

Ex Parte Reexamination Proceedings Resulting from Supplemental Examination Proceedings: Section 12 of the AIA added new 35 U.S.C. 257, which provides for a proceeding titled “supplemental examination” that may be requested by the patent owner to consider, reconsider, or correct information believed to be relevant to the patent in accordance with requirements which have been established by the Office. The information that may be presented in a request for supplemental examination is not limited to patents and printed publications, and may include, for example, issues of patentability under 35 U.S.C. 101 and 35 U.S.C. 112. If the supplemental examination certificate, which is issued under 35 U.S.C. 257(a), states that a substantial new question of patentability is raised by one or more items of information in the request, ex parte reexamination of the patent will be ordered under 35 U.S.C. 257. See MPEP Chapter 2800 for guidance on the procedures for supplemental examination proceedings, and for procedures regarding the order and first Office action mailed in any ex parte reexamination proceeding ordered as a result of a supplemental examination proceeding.

Jump to MPEP SourceFirst Action on Merits (FAOM)Reexamination CertificateSNQ Criteria
Topic

Inter Partes Reexamination

1 rules
StatutoryInformativeAlways
[mpep-2201-47801dc2b615730696c2ca36]
Inter Partes Reexamination Process Changed Post-2012
Note:
The inter partes reexamination process was replaced by an inter partes review process on September 16, 2012, under the Leahy-Smith America Invents Act.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceInter Partes ReexaminationAIA Effective DatesInter Partes Review (IPR)
Topic

Ex Parte Reexamination

1 rules
StatutoryInformativeAlways
[mpep-2201-ea5d1c5fce1782e0972a0093]
Optional Inter Partes Reexamination Added by AIPA
Note:
The American Inventors Protection Act of 1999 authorized the extension of reexamination proceedings through an optional inter partes reexamination procedure in addition to ex parte reexamination.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceEx Parte ReexaminationInter Partes ReexaminationAIA Effective Dates
Topic

Inter Partes Reexamination Appeal

1 rules
StatutoryInformativeAlways
[mpep-2201-5cc7cca863ca8c1f33ce229b]
Final Rules for Inter Partes Reexamination Published
Note:
The final rules to implement the optional inter partes reexamination were published in December 2000 and January 2001.

Inter Partes Reexamination Proceedings: On November 29, 1999, the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113 was enacted, and expanded reexamination by providing an “inter partes” option. The AIPA authorized the extension of reexamination proceedings via an optional inter partes reexamination procedure in addition to ex parte reexamination. 35 U.S.C. 311 – 318 (in effect for inter partes reexaminations filed prior to September 16, 2012) are directed to the optional inter partes reexamination procedures. The final rules to implement the optional inter partes reexamination were published in the Federal Register on December 7, 2000 at 65 FR 76756 and in the Official Gazette on January 2, 2001 at 1242 OG 12. Effective September 16, 2012, section 6(c) of the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, replaced the inter partes reexamination process that was established by the AIPA with an inter partes review process, such that (on or after September 16, 2012) the Office no longer entertains requests for inter partes reexamination but instead accepts petitions to conduct inter partes review before the Board, where appropriate. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 311 – 318 as they were in effect prior to September 16, 2012, continue to apply to the inter partes reexamination proceedings. See MPEP Chapter 2600 for guidance on the procedures for inter partes reexamination proceedings, as well as with respect to an ex parte reexamination proceeding merged (consolidated) with an inter partes reexamination proceeding.

Jump to MPEP SourceInter Partes Reexamination AppealEstoppel After JudgmentInter Partes Reexamination
Topic

Inter Partes Review (IPR)

1 rules
MPEP GuidancePermittedAlways
[mpep-2201-a8ace0fb83359b094b63dbb0]
Estoppel for Filing Ex Parte Reexamination After Final Decision in IPR
Note:
The rule states that an estoppel may prevent filing an ex parte reexamination request after a final written decision in an inter partes review or post grant review proceeding.

On September 16, 2012, the Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted. The AIA expanded the scope of information that any party may cite in a patent file to include written statements of a patent owner filed in a proceeding before a federal court or the United States Patent and Trademark Office (Office) regarding the scope of any claim of the patent, and provides for how such information may be considered in ex parte reexamination, inter partes review, and post grant review. The AIA also provided for an estoppel that may attach with respect to the filing of an ex parte reexamination request subsequent to a final written decision in an inter partes review or post grant review proceeding.

Jump to MPEP SourceInter Partes Review (IPR)Post-Grant Proceedings Under AIAEx Parte Reexamination Request
Topic

AIA vs Pre-AIA Practice

1 rules
MPEP GuidanceInformativeAlways
[mpep-2201-55e6e3f2a9d29f9c4ab35eb6]
First-Inventor-to-File Prior Art Applies Generally
Note:
The rule requires that the first-inventor-to-file prior art regime be applied in reexamination proceedings unless specific conditions are met, in which case pre-AIA rules apply.

The AIA also provided for a first-inventor-to-file prior art regime to replace the first-to-invent prior art regime, with respect to prior art available to be applied to claims. The prior art regime under which the application for the patent was examined (the first-inventor-to-file prior art regime, or the first-to-invent prior art regime) will generally be applied in the reexamination of the patent. However, there are rare exceptions. For example, a situation may arise in which a benefit claim to an application filed before March 16, 2013, is added in a reexamination proceeding based on an AIA patent. If all of the claims that have ever been presented in the reexamination proceeding and the underlying patent are fully supported by the prior application filed before March 16, 2013, and the application which resulted in the patent subject to the reexamination proceeding did not claim, directly or indirectly, the benefit of an application filed in the United States that presented at any time a claim that had an effective filing date on or after March 16, 2013, then the reexamination proceeding would be examined under the pre-AIA, first to invent, provisions.

Jump to MPEP SourceAIA vs Pre-AIA PracticeAIA Effective DatesDetermining Whether Application Is AIA or Pre-AIA

Citations

Primary topicCitation
First Action on Merits (FAOM)
First Office Action on Merits
Statutory Authority for Examination
35 U.S.C. § 101
First Action on Merits (FAOM)
First Office Action on Merits
Statutory Authority for Examination
35 U.S.C. § 112
First Action on Merits (FAOM)
First Office Action on Merits
Statutory Authority for Examination
35 U.S.C. § 257
First Action on Merits (FAOM)
First Office Action on Merits
Statutory Authority for Examination
35 U.S.C. § 257(a)
AIA Effective Dates35 U.S.C. § 302
AIA Effective Dates
Ex Parte Reexamination
Inter Partes Reexamination
Inter Partes Reexamination Appeal
35 U.S.C. § 311
SNQ CriteriaMPEP § 2242

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