What is an office action in patent prosecution?
An office action is written correspondence from a USPTO patent examiner requiring a properly signed written response in order for prosecution of the application to continue. The statutory basis is 35 U.S.C. § 132, which requires the USPTO to notify applicants of any rejection, stating the reasons for such rejection or other requirement, together with information and references useful in judging the propriety of continuing prosecution.
Every pending claim must be accounted for in each office action, and the examiner must answer all applicant arguments and cite the relevant statutory sections behind each rejection. Examiners use Form PTOL-326 (Office Action Summary) as the first page and Form PTO-892 (Notice of References Cited) to list any prior art cited in the action.
Types of office actions
Not every office action is a substantive rejection. Three main categories arise during prosecution:
Restriction requirement
A restriction requirement is issued when an application claims two or more independent and distinct inventions, requiring the applicant to elect one invention to pursue in that application. Claims to non-elected inventions are withdrawn from further consideration. Under 35 U.S.C. § 121, the non-elected invention may be made the subject of a divisional application.
A restriction requirement typically arrives before substantive examination of the merits. Electing under protest is permitted and can preserve the right to petition against the requirement later.
Non-final office action
A non-final office action is an action on the first examination of the application on its merits; because it is adverse in some respect, the applicant must reply requesting reconsideration or further examination, with or without amendment. The reply must be in writing, must distinctly and specifically point out the supposed errors in the examiner's action, and must address every ground of objection and rejection.
Final office action
A final rejection becomes proper on the second or subsequent office action, except when the examiner introduces a new ground of rejection not necessitated by the applicant's amendments. At that stage, the applicant's response options narrow: the reply is limited to appeal of rejected claims to the Patent Trial and Appeal Board, or amendment as specified in 37 CFR 1.114 or 1.116. Amendments submitted after a final rejection are approved for entry only if they place the application in condition for allowance or in better form for appeal.
Common grounds for rejection in substantive office actions
Most substantive office actions combine one or more of the following rejection types:
| Statute | Ground | Core question |
|---|---|---|
| 35 U.S.C. § 101 | Patent eligibility | Is the invention within a statutory category and does it have utility? |
| 35 U.S.C. § 102 | Novelty | Does a single prior art reference anticipate every element of a claim? |
| 35 U.S.C. § 103 | Non-obviousness | Would the claimed invention have been obvious to a skilled artisan? |
| 35 U.S.C. § 112 | Specification requirements | Does the specification satisfy written description, enablement, and definiteness? |
A § 101 rejection asserts that the claimed invention falls outside the statutory categories of a new and useful process, machine, manufacture, or composition of matter, or that it lacks utility. A § 102 rejection asserts that the claim is anticipated because each and every element of the claim is found, expressly or inherently, in a single prior art reference, so the invention lacks novelty. A § 103 rejection asserts that the claimed invention, while novel, would have been obvious to a person of ordinary skill in the art. A § 112 rejection asserts that the specification fails a written description, enablement, or claim definiteness requirement.
Practical notes for practitioners
Address every ground. A reply that does not engage with each rejection and objection the examiner raised is not a bona fide attempt to advance the application. Examiners are expected to raise all applicable grounds in the first action; a complete first response avoids compounding prosecution.
A final rejection is not the end of the road. The applicant may file a Request for Continued Examination under 37 CFR 1.114 to reopen prosecution, file a notice of appeal to the Patent Trial and Appeal Board, or submit an after-final amendment under 37 CFR 1.116 that places the application in condition for allowance.
Arguments build the prosecution history. Every position taken in response to an office action becomes part of the application's prosecution history. The USPTO and courts use that record when interpreting claim scope, so practitioners weigh the long-term effect of narrowing arguments against the short-term benefit of clearing a rejection.
Watch for new grounds in a final. If a final office action introduces a rejection on grounds not necessitated by the applicant's amendments, that finality may be improper under the MPEP. Petitioning against an improper final rejection can reopen the non-final track and preserve amendment rights.