MPEP § 2601 — Introduction (Annotated Rules)

§2601 Introduction

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

This page consolidates and annotates all enforceable requirements under MPEP § 2601, 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.

Key Rules

Topic

AIA Effective Dates

4 rules
StatutoryInformativeAlways
[mpep-2601-b1a8d854c9ab748ec337889f]
Optional Inter Partes Reexamination Added by AIPA
Note:
The American Inventors Protection Act of 1999 introduced the optional inter partes reexamination procedure on November 29, 1999.

The optional inter partes reexamination procedure was added to the existing ex parte reexamination procedure on November 29, 1999 in the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113, app. I, title IV, 113 Stat. 1501, 1501A-552 through 1501A-591. Sections 311 – 318 of title 35 of the United States Code were added by the AIPA and were subsequently amended on November 2, 2002 by Public Law 107-273, div. C, title III, subtitles A and B, 116 Stat. 1758, 1899 through 1906. The Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted on September 16, 2011 and replaced the optional inter partes reexamination procedure with the inter partes review process. Pursuant to the AIA, the Office does not accept requests for inter partes reexamination filed on or after September 16, 2012 (see 37 CFR 1.913(b)), but instead accepts petitions to conduct inter partes review. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 31135 U.S.C. 318 as they were in effect prior to September 16, 2012 continue to apply to the inter partes reexamination proceedings.

Jump to MPEP Source · 37 CFR 1.913(b))AIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2601-d5d734385345b9246b965181]
Inter Partes Review Process Replaced Optional Inter Partes Reexamination
Note:
The AIA replaced the optional inter partes reexamination procedure with an inter partes review process, effective September 16, 2012.

The optional inter partes reexamination procedure was added to the existing ex parte reexamination procedure on November 29, 1999 in the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113, app. I, title IV, 113 Stat. 1501, 1501A-552 through 1501A-591. Sections 311 – 318 of title 35 of the United States Code were added by the AIPA and were subsequently amended on November 2, 2002 by Public Law 107-273, div. C, title III, subtitles A and B, 116 Stat. 1758, 1899 through 1906. The Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted on September 16, 2011 and replaced the optional inter partes reexamination procedure with the inter partes review process. Pursuant to the AIA, the Office does not accept requests for inter partes reexamination filed on or after September 16, 2012 (see 37 CFR 1.913(b)), but instead accepts petitions to conduct inter partes review. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 31135 U.S.C. 318 as they were in effect prior to September 16, 2012 continue to apply to the inter partes reexamination proceedings.

Jump to MPEP Source · 37 CFR 1.913(b))AIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2601-0fda624797517c41c4995899]
Inter Partes Review Required After AIA
Note:
The Office requires petitions for inter partes review instead of requests for inter partes reexamination on or after September 16, 2012.

The optional inter partes reexamination procedure was added to the existing ex parte reexamination procedure on November 29, 1999 in the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113, app. I, title IV, 113 Stat. 1501, 1501A-552 through 1501A-591. Sections 311 – 318 of title 35 of the United States Code were added by the AIPA and were subsequently amended on November 2, 2002 by Public Law 107-273, div. C, title III, subtitles A and B, 116 Stat. 1758, 1899 through 1906. The Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted on September 16, 2011 and replaced the optional inter partes reexamination procedure with the inter partes review process. Pursuant to the AIA, the Office does not accept requests for inter partes reexamination filed on or after September 16, 2012 (see 37 CFR 1.913(b)), but instead accepts petitions to conduct inter partes review. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 31135 U.S.C. 318 as they were in effect prior to September 16, 2012 continue to apply to the inter partes reexamination proceedings.

Jump to MPEP Source · 37 CFR 1.913(b))AIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
StatutoryInformativeAlways
[mpep-2601-2fcc24ee3c2185d3c1e5f220]
Provisions for Inter Partes Reexaminations Filed Before AIA Effective Date
Note:
The rules governing inter partes reexaminations filed before September 16, 2012, continue to apply as they were prior to the America Invents Act's implementation.

The optional inter partes reexamination procedure was added to the existing ex parte reexamination procedure on November 29, 1999 in the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113, app. I, title IV, 113 Stat. 1501, 1501A-552 through 1501A-591. Sections 311 – 318 of title 35 of the United States Code were added by the AIPA and were subsequently amended on November 2, 2002 by Public Law 107-273, div. C, title III, subtitles A and B, 116 Stat. 1758, 1899 through 1906. The Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted on September 16, 2011 and replaced the optional inter partes reexamination procedure with the inter partes review process. Pursuant to the AIA, the Office does not accept requests for inter partes reexamination filed on or after September 16, 2012 (see 37 CFR 1.913(b)), but instead accepts petitions to conduct inter partes review. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 31135 U.S.C. 318 as they were in effect prior to September 16, 2012 continue to apply to the inter partes reexamination proceedings.

Jump to MPEP Source · 37 CFR 1.913(b))AIA Effective DatesInter Partes Review (IPR)AIA Overview and Effective Dates
Topic

Inter Partes Review (IPR)

1 rules
StatutoryInformativeAlways
[mpep-2601-fc3298766c3b6db0db8a7591]
AIA Replaces Optional Inter partes Reexamination With IPR
Note:
The Leahy-Smith America Invents Act replaced the optional inter partes reexamination procedure with the inter partes review process.

The optional inter partes reexamination procedure was added to the existing ex parte reexamination procedure on November 29, 1999 in the American Inventors Protection Act of 1999 (the AIPA), Public Law 106-113, app. I, title IV, 113 Stat. 1501, 1501A-552 through 1501A-591. Sections 311 – 318 of title 35 of the United States Code were added by the AIPA and were subsequently amended on November 2, 2002 by Public Law 107-273, div. C, title III, subtitles A and B, 116 Stat. 1758, 1899 through 1906. The Leahy-Smith America Invents Act (the AIA), Public Law 112-29, 125 Stat. 284, was enacted on September 16, 2011 and replaced the optional inter partes reexamination procedure with the inter partes review process. Pursuant to the AIA, the Office does not accept requests for inter partes reexamination filed on or after September 16, 2012 (see 37 CFR 1.913(b)), but instead accepts petitions to conduct inter partes review. For any inter partes reexamination filed prior to September 16, 2012, the provisions of 35 U.S.C. 31135 U.S.C. 318 as they were in effect prior to September 16, 2012 continue to apply to the inter partes reexamination proceedings.

Jump to MPEP Source · 37 CFR 1.913(b))Inter Partes Review (IPR)AIA Overview and Effective DatesPost-Grant Proceedings Under AIA
Topic

Ex Parte Reexamination

1 rules
StatutoryInformativeAlways
[mpep-2601-06a62462f781d1172643938e]
Ex Parte Reexamination Option Available
Note:
The option for ex parte reexamination is still available, and guidance on the procedures can be found in MPEP sections 2209 to 2296.

The ex parte reexamination option is still available. See MPEP §§ 2209 to 2296 for guidance on the procedures for ex parte reexamination proceedings.

Jump to MPEP SourceEx Parte Reexamination

Citations

Primary topicCitation
AIA Effective Dates
Inter Partes Review (IPR)
35 U.S.C. § 311
AIA Effective Dates
Inter Partes Review (IPR)
35 U.S.C. § 318
AIA Effective Dates
Inter Partes Review (IPR)
37 CFR § 1.913(b)
Ex Parte ReexaminationMPEP § 2209

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