MPEP § 901.04 — U.S. Patents (Annotated Rules)

§901.04 U.S. Patents

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

This page consolidates and annotates all enforceable requirements under MPEP § 901.04, 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.

U.S. Patents

This section addresses U.S. Patents. Primary authority: 35 U.S.C. 102(e), 35 U.S.C. 102(a)(2), and 35 U.S.C. 307. Contains: 1 requirement, 1 guidance statement, and 12 other statements.

Key Rules

Topic

Sequence Listing Format

4 rules
StatutoryInformativeAlways
[mpep-901-04-d2407e3d942e031b3c5f3665]
Sequence Listing Not Numbered
Note:
Patents issued between 1790 and July 4, 1836 are not numbered but must be identified by the patentee’s name and date of issue.

X-Series. These are the approximately 10,000 patents issued between 1790 and July 4, 1836. They were not originally numbered, but have since been assigned numbers in the sequence in which they were issued. The number should not be cited. When copies are ordered, the patentee’s name and date of issue suffice for identification.

Jump to MPEP SourceSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-901-04-ab553bb6cec6bdb4259ce991]
Patents Were Assigned Sequential Numbers
Note:
Patents issued between 1790 and July 4, 1836 were not originally numbered but have since been assigned sequential numbers for identification purposes.

X-Series. These are the approximately 10,000 patents issued between 1790 and July 4, 1836. They were not originally numbered, but have since been assigned numbers in the sequence in which they were issued. The number should not be cited. When copies are ordered, the patentee’s name and date of issue suffice for identification.

Jump to MPEP SourceSequence Listing FormatSequence Listing Requirements
StatutoryRecommendedAlways
[mpep-901-04-14c88c1fb1b593f7c9434dca]
Number Not Required for Identification
Note:
Patents issued between 1790 and July 4, 1836 do not require the citation of a number for identification purposes. Copies can be ordered using the patentee’s name and date of issue.

X-Series. These are the approximately 10,000 patents issued between 1790 and July 4, 1836. They were not originally numbered, but have since been assigned numbers in the sequence in which they were issued. The number should not be cited. When copies are ordered, the patentee’s name and date of issue suffice for identification.

Jump to MPEP SourceSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-901-04-16d30dbd26e3bc374ced87f1]
Identification of X-Series Patents Sufficient
Note:
When copies of patents issued between 1790 and July 4, 1836 are ordered, the patentee’s name and date of issue are sufficient for identification.

X-Series. These are the approximately 10,000 patents issued between 1790 and July 4, 1836. They were not originally numbered, but have since been assigned numbers in the sequence in which they were issued. The number should not be cited. When copies are ordered, the patentee’s name and date of issue suffice for identification.

Jump to MPEP SourceSequence Listing FormatSequence Listing Requirements
Topic

Reexamination Certificate

4 rules
StatutoryInformativeAlways
[mpep-901-04-abf61268de81ea192d87999c]
Changes Incorporated Into Patent Upon Publication
Note:
Any changes made during reexamination are incorporated into the patent upon publication of the certificate, with no enlargement of claim scope or introduction of new matter.

Reexamination Certificates. A reexamination proceeding is concluded by the issuance and publication of a reexamination certificate, which indicates all changes to the specification, including the claims, and drawings. Any changes made during the reexamination proceeding may not enlarge the scope of the claims or introduce new matter. Upon publication of the reexamination certificate, all changes are incorporated into the patent. Accordingly, the prior art date for subject matter in the reexamination certificate is the same as the prior art date for the patent that was reexamined. See 35 U.S.C. 307 and pre-AIA 35 U.S.C. 316.

Jump to MPEP SourceReexamination CertificateConclusion of Ex Parte ReexaminationEx Parte Reexamination
StatutoryInformativeAlways
[mpep-901-04-53132352965ba13217d4e1d6]
Reexamination Conclusion Is Marked by Issuance of Reexamination Certificate
Note:
The reexamination proceeding concludes with the issuance and publication of a certificate that reflects all changes to the specification, claims, and drawings.

Reexamination Certificates. A reexamination proceeding is concluded by the issuance and publication of a reexamination certificate, which indicates all changes to the specification, including the claims, and drawings. Any changes made during the reexamination proceeding may not enlarge the scope of the claims or introduce new matter. Upon publication of the reexamination certificate, all changes are incorporated into the patent. Accordingly, the prior art date for subject matter in the reexamination certificate is the same as the prior art date for the patent that was reexamined. See 35 U.S.C. 307 and pre-AIA 35 U.S.C. 316.

Jump to MPEP SourceReexamination CertificateConclusion of Ex Parte ReexaminationEx Parte Reexamination
StatutoryInformativeAlways
[mpep-901-04-41b9fa0091705c857e449310]
Changes Incorporated Upon Publication
Note:
All changes made during reexamination are incorporated into the patent upon publication of the reexamination certificate.

Reexamination Certificates. A reexamination proceeding is concluded by the issuance and publication of a reexamination certificate, which indicates all changes to the specification, including the claims, and drawings. Any changes made during the reexamination proceeding may not enlarge the scope of the claims or introduce new matter. Upon publication of the reexamination certificate, all changes are incorporated into the patent. Accordingly, the prior art date for subject matter in the reexamination certificate is the same as the prior art date for the patent that was reexamined. See 35 U.S.C. 307 and pre-AIA 35 U.S.C. 316.

Jump to MPEP SourceReexamination CertificateConclusion of Ex Parte ReexaminationEx Parte Reexamination
StatutoryInformativeAlways
[mpep-901-04-83e6454541a94e7dad9b2d54]
Prior Art Date for Reexam Certificate Matches Original Patent
Note:
The prior art date for changes made in a reexamination certificate is the same as the original patent's prior art date.

Reexamination Certificates. A reexamination proceeding is concluded by the issuance and publication of a reexamination certificate, which indicates all changes to the specification, including the claims, and drawings. Any changes made during the reexamination proceeding may not enlarge the scope of the claims or introduce new matter. Upon publication of the reexamination certificate, all changes are incorporated into the patent. Accordingly, the prior art date for subject matter in the reexamination certificate is the same as the prior art date for the patent that was reexamined. See 35 U.S.C. 307 and pre-AIA 35 U.S.C. 316.

Jump to MPEP SourceReexamination CertificateConclusion of Ex Parte ReexaminationEx Parte Reexamination
Topic

AIA Effective Dates

3 rules
StatutoryInformativeAlways
[mpep-901-04-96245892034b1ee76198d5b3]
Effective Date for U.S. Patents
Note:
Describes how the filing date and publication date determine the effective date of a U.S. patent, including pre-AIA and AIA rules.

The following different series of U.S. patents are being or in the past have been issued. The date of patenting given on the face of each copy is the publication date and is the one usually cited. The filing date, in most instances also given on the face of the patent, is ordinarily the effective date as a reference. See MPEP §§ 2127, subsection II, 2136 and 2154. The pre-AIA 35 U.S.C. 102(e) date of a U.S. patent can be an earlier effective U.S. filing date. See MPEP § 2136 et seq. The 35 U.S.C. 102(a)(2) prior art date of a U.S. patent issued from a nonprovisional application claiming the benefit of a prior domestic application or priority to a foreign filed application may be the filing date of the prior filed application. See MPEP § 2154.01(b).

Jump to MPEP SourceAIA Effective DatesAIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)Pre-AIA 102(e) – Earlier US Applications (MPEP 2136)
StatutoryInformativeAlways
[mpep-901-04-e04d650c7a47fd2250e120ff]
Publication Date Is Usually Cited
Note:
The date of patenting on the face of each copy is considered the publication date and is typically cited.

The following different series of U.S. patents are being or in the past have been issued. The date of patenting given on the face of each copy is the publication date and is the one usually cited. The filing date, in most instances also given on the face of the patent, is ordinarily the effective date as a reference. See MPEP §§ 2127, subsection II, 2136 and 2154. The pre-AIA 35 U.S.C. 102(e) date of a U.S. patent can be an earlier effective U.S. filing date. See MPEP § 2136 et seq. The 35 U.S.C. 102(a)(2) prior art date of a U.S. patent issued from a nonprovisional application claiming the benefit of a prior domestic application or priority to a foreign filed application may be the filing date of the prior filed application. See MPEP § 2154.01(b).

Jump to MPEP SourceAIA Effective DatesAIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)Pre-AIA 102(e) – Earlier US Applications (MPEP 2136)
StatutoryInformativeAlways
[mpep-901-04-97d94bdbf92d98636643a191]
Filing Date as Effective Reference for Patents
Note:
The filing date, typically found on the patent face, serves as the effective reference date unless otherwise specified.

The following different series of U.S. patents are being or in the past have been issued. The date of patenting given on the face of each copy is the publication date and is the one usually cited. The filing date, in most instances also given on the face of the patent, is ordinarily the effective date as a reference. See MPEP §§ 2127, subsection II, 2136 and 2154. The pre-AIA 35 U.S.C. 102(e) date of a U.S. patent can be an earlier effective U.S. filing date. See MPEP § 2136 et seq. The 35 U.S.C. 102(a)(2) prior art date of a U.S. patent issued from a nonprovisional application claiming the benefit of a prior domestic application or priority to a foreign filed application may be the filing date of the prior filed application. See MPEP § 2154.01(b).

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
Topic

Reissue Patent Practice

3 rules
StatutoryInformativeAlways
[mpep-901-04-1a59a0f66893c61349c2762a]
Reissue Patents Require Specific Numbering
Note:
Patents must be cited with the 'Re.' prefix and their specific number, using the original application's effective date as the reference.

Reissue Series. Reissue patents (see MPEP § 1401) have been given a separate series of numbers preceded by “Re.” In citing, the letters and the number must be given, e.g., Re. 1776. The date that it is effective as a reference is the effective date of the original patent application, not the filing date of the reissue application.

Jump to MPEP SourceReissue Patent PracticeReissue Application FilingReissue Claim Requirements
StatutoryInformativeAlways
[mpep-901-04-17919d55b73b8901e87e2f01]
Reissue Patents Require Specific Numbering
Note:
Reissued patents must use a separate series of numbers starting with 'Re.' and include the date as the original patent application's effective date.

Reissue Series. Reissue patents (see MPEP § 1401) have been given a separate series of numbers preceded by “Re.” In citing, the letters and the number must be given, e.g., Re. 1776. The date that it is effective as a reference is the effective date of the original patent application, not the filing date of the reissue application.

Jump to MPEP SourceReissue Patent PracticeReissue Application FilingReissue Claim Requirements
StatutoryInformativeAlways
[mpep-901-04-dcbaad8a7ba5d67f2016909f]
Correction for Patent Errors Required
Note:
A certificate of correction fixes errors in the patent and is considered part of the original patent, maintaining its prior art effect.

Certificates of Correction. A certificate of correction corrects errors in the patent and is considered as part of the original patent. A patent, together with its certificate of correction, will have the same prior art effect as if the original patent was issued in the corrected form. See 35 U.S.C. 254 and 255.

Jump to MPEP SourceReissue Patent PracticePrior Art in ReissueReissue Examination
Topic

Plant Patent Practice

3 rules
StatutoryInformativeAlways
[mpep-901-04-8287cdd1d6f3cb8be39637f3]
Plant Patents Require Separate Numbering
Note:
When patenting certain types of plants, patents are given a separate series number starting with P.P., which must be cited accordingly.

Plant Patent Series. When the statutes were amended to provide for patenting certain types of plants (see MPEP Chapter 1600) these patents were given a separate series of numbers. In citing, the letters “P.P.” and the number must be given, e.g., P.P. 13.

Jump to MPEP SourcePlant Patent Practice
StatutoryInformativeAlways
[mpep-901-04-733d82292cca24dc1eedd809]
Separate Numbering for Plant Patents
Note:
Patents for certain types of plants are given a distinct series of numbers when the statutes were amended.

Plant Patent Series. When the statutes were amended to provide for patenting certain types of plants (see MPEP Chapter 1600) these patents were given a separate series of numbers. In citing, the letters “P.P.” and the number must be given, e.g., P.P. 13.

Jump to MPEP SourcePlant Patent Practice
StatutoryRequiredAlways
[mpep-901-04-87b4a56ac224175974fe62fb]
Plant Patents Must Use P.P. Series
Note:
Plant patents must be cited using the series number preceded by 'P.P.', e.g., P.P. 13.

Plant Patent Series. When the statutes were amended to provide for patenting certain types of plants (see MPEP Chapter 1600) these patents were given a separate series of numbers. In citing, the letters “P.P.” and the number must be given, e.g., P.P. 13.

Jump to MPEP SourcePlant Patent Practice
Topic

AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)

2 rules
StatutoryPermittedAlways
[mpep-901-04-e34cde6a47651e520d088a41]
Pre-AIA 102(e) Patent Can Have Earlier Filing Date
Note:
A U.S. patent issued under pre-AIA law can have an effective filing date that is earlier than the publication date, based on a prior domestic application or foreign filed application.

The following different series of U.S. patents are being or in the past have been issued. The date of patenting given on the face of each copy is the publication date and is the one usually cited. The filing date, in most instances also given on the face of the patent, is ordinarily the effective date as a reference. See MPEP §§ 2127, subsection II, 2136 and 2154. The pre-AIA 35 U.S.C. 102(e) date of a U.S. patent can be an earlier effective U.S. filing date. See MPEP § 2136 et seq. The 35 U.S.C. 102(a)(2) prior art date of a U.S. patent issued from a nonprovisional application claiming the benefit of a prior domestic application or priority to a foreign filed application may be the filing date of the prior filed application. See MPEP § 2154.01(b).

Jump to MPEP SourceAIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)Pre-AIA 102(e) – Earlier US Applications (MPEP 2136)
StatutoryPermittedAlways
[mpep-901-04-009fa01801300597dfbd8111]
AIA 102(a)(2) Prior Art Date May Be Earlier Filed Application
Note:
The prior art date for a U.S. patent can be the filing date of an earlier domestic or foreign application claimed in a nonprovisional application.

The following different series of U.S. patents are being or in the past have been issued. The date of patenting given on the face of each copy is the publication date and is the one usually cited. The filing date, in most instances also given on the face of the patent, is ordinarily the effective date as a reference. See MPEP §§ 2127, subsection II, 2136 and 2154. The pre-AIA 35 U.S.C. 102(e) date of a U.S. patent can be an earlier effective U.S. filing date. See MPEP § 2136 et seq. The 35 U.S.C. 102(a)(2) prior art date of a U.S. patent issued from a nonprovisional application claiming the benefit of a prior domestic application or priority to a foreign filed application may be the filing date of the prior filed application. See MPEP § 2154.01(b).

Jump to MPEP SourceAIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)Pre-AIA 102(e) – Earlier US Applications (MPEP 2136)Novelty / Prior Art
Topic

Reissue Application Filing

2 rules
StatutoryRequiredAlways
[mpep-901-04-839369482e0027186bf4b3ac]
Reissue Patents Must Use Specific Numbering
Note:
Reissue patents must be cited with the 'Re.' prefix followed by a specific number, e.g., Re. 1776.

Reissue Series. Reissue patents (see MPEP § 1401) have been given a separate series of numbers preceded by “Re.” In citing, the letters and the number must be given, e.g., Re. 1776. The date that it is effective as a reference is the effective date of the original patent application, not the filing date of the reissue application.

Jump to MPEP SourceReissue Application FilingReissue Claim RequirementsReissue Patent Practice
StatutoryInformativeAlways
[mpep-901-04-7eeb14be0e9825c190bcb5f1]
Effective Date Is Original Application
Note:
The effective date for a reissue patent is based on the original application's filing date, not the reissue application's filing date.

Reissue Series. Reissue patents (see MPEP § 1401) have been given a separate series of numbers preceded by “Re.” In citing, the letters and the number must be given, e.g., Re. 1776. The date that it is effective as a reference is the effective date of the original patent application, not the filing date of the reissue application.

Jump to MPEP SourceReissue Application FilingReissue Claim RequirementsReissue Patent Practice
Topic

Prior Art in Reissue

2 rules
StatutoryInformativeAlways
[mpep-901-04-eac6a0cccd201e32c705a29b]
Correction Certificate Is Part of Patent
Note:
A certificate of correction corrects errors in the patent and is considered part of the original patent, maintaining its prior art effect.

Certificates of Correction. A certificate of correction corrects errors in the patent and is considered as part of the original patent. A patent, together with its certificate of correction, will have the same prior art effect as if the original patent was issued in the corrected form. See 35 U.S.C. 254 and 255.

Jump to MPEP SourcePrior Art in ReissueReissue ExaminationReissue Patent Practice
StatutoryInformativeAlways
[mpep-901-04-701958ad1c9242a94782a04b]
Certificates of Correction Have Same Prior Art Effect as Original Patent
Note:
A patent with its certificate of correction has the same prior art effect as if it was originally issued in the corrected form.

Certificates of Correction. A certificate of correction corrects errors in the patent and is considered as part of the original patent. A patent, together with its certificate of correction, will have the same prior art effect as if the original patent was issued in the corrected form. See 35 U.S.C. 254 and 255.

Jump to MPEP SourcePrior Art in ReissueReissue ExaminationReissue Patent Practice
Topic

Patent Expiration for Nonpayment

2 rules
StatutoryInformativeAlways
[mpep-901-04-ca011e0849923774c809df1f]
Derivation Certificate Issuance Upon Adverse Decision
Note:
If a patent's claims are found invalid in a derivation proceeding and no appeal is taken, the Office issues a certificate canceling those claims.

Derivation Certificates. At the conclusion of a derivation proceeding, if the final decision of the PTAB is adverse to claims in a patent, and the time for appeal has expired or any appeal or other review of the decision has terminated, the Office will issue and publish a derivation certificate canceling those claims of the patent. Inventorship of a patent may also be corrected via a derivation proceeding.

Jump to MPEP SourcePatent Expiration for NonpaymentEx Parte Appeals to PTABDerivation Proceedings (AIA)
StatutoryInformativeAlways
[mpep-901-04-3a1a1cec61fdc4b347f90711]
Derivation Certificate Issued for Adverse PTAB Decision
Note:
If the PTAB's final decision in a derivation proceeding is adverse to patent claims and no appeal is filed or terminated, the Office will issue a derivation certificate canceling those claims.

Derivation Certificates. At the conclusion of a derivation proceeding, if the final decision of the PTAB is adverse to claims in a patent, and the time for appeal has expired or any appeal or other review of the decision has terminated, the Office will issue and publish a derivation certificate canceling those claims of the patent. Inventorship of a patent may also be corrected via a derivation proceeding.

Jump to MPEP SourcePatent Expiration for NonpaymentEx Parte Appeals to PTABDerivation Proceedings (AIA)
Topic

Ex Parte Reexamination

1 rules
StatutoryProhibitedAlways
[mpep-901-04-818ff68969d9143d97ffa6e0]
Claims Must Not Enlarge Scope During Reexamination
Note:
Changes made during reexamination must not expand the claim scope or introduce new matter.

Reexamination Certificates. A reexamination proceeding is concluded by the issuance and publication of a reexamination certificate, which indicates all changes to the specification, including the claims, and drawings. Any changes made during the reexamination proceeding may not enlarge the scope of the claims or introduce new matter. Upon publication of the reexamination certificate, all changes are incorporated into the patent. Accordingly, the prior art date for subject matter in the reexamination certificate is the same as the prior art date for the patent that was reexamined. See 35 U.S.C. 307 and pre-AIA 35 U.S.C. 316.

Jump to MPEP SourceEx Parte ReexaminationReexamination CertificateConclusion of Ex Parte Reexamination
Topic

Derivation Proceedings (AIA)

1 rules
StatutoryPermittedAlways
[mpep-901-04-ac624d236142841a0ab6a6e5]
Inventorship Can Be Corrected Via Derivation Proceeding
Note:
Patent inventorship may be corrected through a derivation proceeding if the PTAB's final decision is adverse to claims in the patent and appeals have been exhausted.

Derivation Certificates. At the conclusion of a derivation proceeding, if the final decision of the PTAB is adverse to claims in a patent, and the time for appeal has expired or any appeal or other review of the decision has terminated, the Office will issue and publish a derivation certificate canceling those claims of the patent. Inventorship of a patent may also be corrected via a derivation proceeding.

Jump to MPEP SourceDerivation Proceedings (AIA)Patent Expiration for NonpaymentEx Parte Appeals to PTAB

Citations

Primary topicCitation
AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
AIA Effective Dates
35 U.S.C. § 102(a)(2)
AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
AIA Effective Dates
35 U.S.C. § 102(e)
Prior Art in Reissue
Reissue Patent Practice
35 U.S.C. § 254
Ex Parte Reexamination
Reexamination Certificate
35 U.S.C. § 307
Ex Parte Reexamination
Reexamination Certificate
35 U.S.C. § 316
Reissue Application Filing
Reissue Patent Practice
MPEP § 1401
AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
AIA Effective Dates
MPEP § 2127
AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
AIA Effective Dates
MPEP § 2136
AIA 102(a)(2) – Earlier Filed Applications (MPEP 2154)
AIA Effective Dates
MPEP § 2154.01(b)
MPEP § 901.05(b)

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