MPEP § 2251 — Reply by Third Party Requester (Annotated Rules)

§2251 Reply by Third Party Requester

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

This page consolidates and annotates all enforceable requirements under MPEP § 2251, 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.

Reply by Third Party Requester

This section addresses Reply by Third Party Requester. Primary authority: 35 U.S.C. 304, 37 CFR 1.530, and 37 CFR 1.248. Contains: 2 requirements, 1 prohibition, 3 permissions, and 5 other statements.

Key Rules

Topic

Third Party Requester Rights

9 rules
StatutoryPermittedAlways
[mpep-2251-cec744a04ff660d5f758ed96]
Ex Parte Requester Must File Reply Within Two Months
Note:
The ex parte reexamination requester must file a reply to the patent owner's statement within two months of receiving it.

A reply to the patent owner’s statement under § 1.530 may be filed by the ex parte reexamination requester within two months from the date of service of the patent owner’s statement. Any reply by the ex parte requester must be served upon the patent owner in accordance with § 1.248. If the patent owner does not file a statement under § 1.530, no reply or other submission from the ex parte reexamination requester will be considered.

Jump to MPEP Source · 37 CFR 1.530Third Party Requester RightsPatent Owner StatementEx Parte Reexamination
StatutoryRequiredAlways
[mpep-2251-1284bda886fc38559a825886]
Reply by Ex Parte Requester Must Be Served on Patent Owner
Note:
The ex parte requester must serve any reply to the patent owner’s statement in accordance with § 1.248.

A reply to the patent owner’s statement under § 1.530 may be filed by the ex parte reexamination requester within two months from the date of service of the patent owner’s statement. Any reply by the ex parte requester must be served upon the patent owner in accordance with § 1.248. If the patent owner does not file a statement under § 1.530, no reply or other submission from the ex parte reexamination requester will be considered.

Jump to MPEP Source · 37 CFR 1.530Third Party Requester RightsThird Party Requester ReplyInter Partes Reexamination Request
StatutoryInformativeAlways
[mpep-2251-818d2a36751b48ebdf7abff3]
No Reply Without Patent Owner Statement
Note:
If the patent owner does not file a statement under §1.530, any reply from the ex parte reexamination requester will not be considered.

A reply to the patent owner’s statement under § 1.530 may be filed by the ex parte reexamination requester within two months from the date of service of the patent owner’s statement. Any reply by the ex parte requester must be served upon the patent owner in accordance with § 1.248. If the patent owner does not file a statement under § 1.530, no reply or other submission from the ex parte reexamination requester will be considered.

Jump to MPEP Source · 37 CFR 1.530Third Party Requester RightsPatent Owner StatementPTAB Jurisdiction
StatutoryInformativeAlways
[mpep-2251-19f0637bca9227e01e6cdaf9]
Third Party Requester Must Reply Within 2 Months
Note:
The third party requester must submit a reply within 2 months from the date of service if the patent owner files a timely statement.

If the patent owner files a statement in a timely manner, the third party requester is given a period of 2 months from the date of service to reply. Since the statute, 35 U.S.C. 304, provides this time period, there will be no extensions of time granted.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsInter Partes Reexamination RequestInter Partes Reexamination
StatutoryPermittedAlways
[mpep-2251-274382e8cf221db47ba1823b]
Third Party Requester Must Not File Statement
Note:
The third party requester is not permitted to file a reply if the patent owner does not file a statement.

If no statement is filed by the patent owner, no reply is permitted from the third party requester.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsInter Partes Reexamination RequestInter Partes Reexamination
StatutoryRequiredAlways
[mpep-2251-bef8a927ad18b9150ea256cc]
Third Party Requester Must Serve Reply on Patent Owner
Note:
The third party requester must provide a copy of their reply to the patent owner in ex parte reexamination proceedings.

The third party requester must serve a copy of the reply on the patent owner. See MPEP § 2266.03 for further discussion as to the third party requester providing service on the patent owner.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsInter Partes Reexamination RequestInter Partes Reexamination
StatutoryPermittedAlways
[mpep-2251-c5160b0c7954b6292bbbda7c]
Reply by Third Party Requester Not Acceptable After Response
Note:
The third party requester is not allowed to submit any additional papers after responding to the patent owner’s statement.

The third party requester is not permitted to file any further papers after his or her reply to the patent owner’s statement. Any further papers will not be considered and will be returned to the requester. The patent owner cannot file papers on behalf of the third party requester and thereby circumvent the rules.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsInter Partes Reexamination RequestPTAB Jurisdiction
StatutoryInformativeAlways
[mpep-2251-409fe8638334c867215e0cb2]
No Further Papers Allowed for Third Party Requester
Note:
The third party requester is not permitted to file any additional papers after replying to the patent owner’s statement.

The third party requester is not permitted to file any further papers after his or her reply to the patent owner’s statement. Any further papers will not be considered and will be returned to the requester. The patent owner cannot file papers on behalf of the third party requester and thereby circumvent the rules.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsThird Party Requester ReplyEx Parte Reexamination
StatutoryProhibitedAlways
[mpep-2251-f662daa410e9279a1b4ead88]
Patent Owner Cannot File for Third Party
Note:
The patent owner is prohibited from filing papers on behalf of the third party requester to avoid circumventing rules.

The third party requester is not permitted to file any further papers after his or her reply to the patent owner’s statement. Any further papers will not be considered and will be returned to the requester. The patent owner cannot file papers on behalf of the third party requester and thereby circumvent the rules.

Jump to MPEP Source · 37 CFR 1.535Third Party Requester RightsInter Partes Reexamination RequestPTAB Jurisdiction
Topic

Reexamination Order

1 rules
StatutoryInformativeAlways
[mpep-2251-2044b410067119d52d9f93ec]
No Extensions for Third Party Requester Reply
Note:
The rule states that the 2-month time period provided to a third party requester to reply after a timely statement by the patent owner cannot be extended.

If the patent owner files a statement in a timely manner, the third party requester is given a period of 2 months from the date of service to reply. Since the statute, 35 U.S.C. 304, provides this time period, there will be no extensions of time granted.

Jump to MPEP Source · 37 CFR 1.535Reexamination OrderEx Parte ReexaminationThird Party Requester Reply
Topic

Estoppel After Judgment

1 rules
StatutoryInformativeAlways
[mpep-2251-6b5bcbd65beb1e3ce0262b07]
Reply by Third Party Requester in Ex Parte Reexamination Allowed
Note:
The reply need not be limited to the issues raised and may include additional prior art patents for reexamination.

The reply need not be limited to the issues raised in the statement. The reply may include additional prior art patents and printed publications and may raise any issue appropriate for reexamination.

Jump to MPEP Source · 37 CFR 1.535Estoppel After JudgmentThird Party Requester RightsThird Party Requester Reply
Topic

Grounds for Reexamination

1 rules
StatutoryPermittedAlways
[mpep-2251-36abfc9e20200452f34e2220]
Reply May Include Additional Patents and Publications
Note:
The reply in a third party requester's ex parte reexamination can include additional prior art patents and printed publications, as well as raise any appropriate issues for reexamination.

The reply need not be limited to the issues raised in the statement. The reply may include additional prior art patents and printed publications and may raise any issue appropriate for reexamination.

Jump to MPEP Source · 37 CFR 1.535Grounds for ReexaminationThird Party Requester RightsThird Party Requester Reply

Citations

Primary topicCitation
Reexamination Order
Third Party Requester Rights
35 U.S.C. § 304
Third Party Requester Rights37 CFR § 1.248
Third Party Requester Rights37 CFR § 1.530
Third Party Requester RightsMPEP § 2266.03

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