What is patent reissue?
Patent reissue, authorized under 35 U.S.C. § 251, is a procedure that allows a patent owner to surrender an issued patent and have the USPTO reexamine it to correct errors that made the patent 'wholly or partly inoperative or invalid.' When a reissue patent is granted, it replaces the original patent and carries the same expiration date. Common reasons for reissue: the original claims were drafted too narrowly and fail to cover commercially important embodiments of the invention; the specification contains errors that affect the scope of enablement; or the claims contain technical errors that make them broader than the inventor intended.
Broadening vs. narrowing reissue
Reissue applications fall into two categories based on their effect on claim scope. A broadening reissue seeks claims that are broader in at least one respect than any claim in the original patent — typically because the original claims were drafted too narrowly. A broadening reissue must be filed within two years of the original patent grant date, or the right to broadening reissue is permanently lost. A narrowing reissue seeks claims that are narrower than the original — typically to avoid prior art discovered after issuance that would invalidate the original claims, or to correct an inadvertent overbreadth. There is no time limit for filing a narrowing reissue (other than the patent term itself).
The two-year broadening deadline
Section 251(d) establishes a strict two-year deadline for any reissue application that enlarges the scope of claims compared to the original patent. This deadline runs from the issue date of the original patent. A reissue application filed after two years may still narrow the claims or correct specification errors, but cannot broaden any claim in any respect. The two-year rule is designed to prevent patent owners from sitting on their rights while observing the market, then filing broadening reissue applications targeted at competitors' products. Once the deadline passes, the public can rely on the original patent's claim boundaries with certainty. Patent prosecutors should evaluate the original claims soon after issue to determine whether a broadening reissue opportunity exists.
The recapture doctrine
The recapture doctrine is the most important limitation on broadening reissue. It prohibits patent owners from using reissue to reclaim subject matter that was surrendered during the original prosecution in order to overcome a rejection. If an applicant narrowed a claim by amendment — for example, adding a specific limitation to distinguish prior art — the applicant cannot later file a broadening reissue that removes that limitation and effectively recaptures the surrendered subject matter. The recapture analysis asks: (1) Were the reissue claims broader than the original claims in a way that relates back to the narrowing done during prosecution? (2) Was the surrender related to patentability (to distinguish prior art or overcome a rejection)? If both answers are yes, the reissue claim violates recapture and will be rejected under § 251.
Reissue vs. continuation applications
Reissue and continuation applications both allow a patent owner to seek additional or modified claims, but they serve different purposes and have different timing. A reissue requires an issued patent and a showing of error. A continuation application must be filed while the parent application is still pending (before it issues or is abandoned) and can be used to pursue additional or broader claims as a matter of strategy — no error need be shown. Once a patent issues, continuation applications are no longer available. If a patent issues with claims that are too narrow and the two-year broadening reissue window has passed, the patent owner may have no mechanism to broaden the claims. This is why experienced patent prosecutors evaluate whether a continuation is needed before the parent application issues.
Intervening rights in broadening reissue
When a reissue patent broadens the original claims, third parties who were operating lawfully under the original patent (before the reissue was filed) may assert intervening rights as a defense. Under 35 U.S.C. § 252, there are two types: (1) Absolute intervening rights protect any specific products made, used, or sold before the reissue was granted — these activities cannot be the basis for infringement liability. (2) Equitable intervening rights are broader and protect activities undertaken in substantial preparation for making or using the infringing subject matter — for example, investing in machinery, signing contracts, or purchasing materials in reliance on the narrower original patent. Courts weigh equity in determining the scope of equitable intervening rights.
Reissue vs. certificate of correction
For minor errors that do not affect claim scope, a Certificate of Correction (CofC) under 35 U.S.C. § 255 is simpler and faster than reissue. A CofC corrects clerical or typographical errors in the patent document itself — fixing a misspelling, correcting a drawing reference, or correcting an error in the patent number. These corrections can be made by petition without surrendering the patent. A CofC cannot change claim scope or correct substantive errors in the disclosure. Reissue is required when the error is substantive — when it affects what the claims cover, what the specification enables, or whether the patent is valid. The practical test: if correcting the error would require someone reading the patent to understand the claims differently, it requires reissue, not a CofC.
Reissue examination procedure
A reissue application is filed with the USPTO like a new application — it requires filing fees (based on entity size), new formal papers, and typically new or amended claims. The reissue application is assigned to the same art unit as the original patent and examined by a patent examiner who reviews the new or amended claims for patentability over the prior art. The examination may include new office actions and responses. The original patent remains in force during reissue prosecution. Any claim that was in the original patent and is unchanged in the reissue may be confirmed without substantive reexamination — only changed or new claims require fresh examination. The entire prosecution history of both the original application and the reissue is part of the public record and can affect claim interpretation.
Frequently Asked Questions
What is a patent reissue application?
A reissue application, filed under 35 U.S.C. § 251, allows a patent owner to surrender an issued patent and have it reexamined and reissued by the USPTO to correct errors. The error must have caused the patent to be 'wholly or partly inoperative or invalid' — typically because the claims are too narrow (failing to capture the full scope of the inventor's contribution), too broad (claiming more than the inventor was actually entitled to), or because the specification contains errors. Only the patent owner can file a reissue; third parties cannot. The resulting reissue patent replaces the original patent and has the same expiration date.
What is the two-year rule for broadening reissue?
Under 35 U.S.C. § 251(d), a reissue application that seeks claims broader than any claim in the original patent must be filed within two years of the date the original patent issued. This is called the 'broadening reissue' deadline. After two years, broadening reissue is not permitted — the patent owner can still file a narrowing reissue (to narrow claims or correct specification errors), but cannot expand claim scope. The two-year window is strictly construed. A reissue application is considered 'broadening' if it seeks any claim broader in any respect than the original claims — it does not need to be broader in all respects, only in some material respect.
What is the recapture rule in reissue?
The recapture doctrine prevents a patent owner from using reissue to recapture subject matter that was deliberately surrendered during the original prosecution to overcome a rejection. If during prosecution the applicant narrowed a claim or made arguments that disclaimed certain subject matter in order to obtain allowance, reissue cannot be used to walk back that surrender. The recapture rule applies when: (1) the original claims were narrowed by amendment or argument to avoid prior art; and (2) the reissue claims are broadened to cover the surrendered subject matter. Courts and the USPTO analyze whether the broader reissue claims are 'materially the same' as the original claims before the narrowing amendment — if so, the reissue claims violate the recapture rule and will be rejected.
What errors can be corrected by a certificate of correction vs. reissue?
A certificate of correction (CofC) under 35 U.S.C. § 255 corrects minor clerical errors, typographical errors, or USPTO errors in an issued patent — without surrendering the patent or going through re-examination of the claims. Examples: correcting a misspelling of the inventor's name, fixing a typographical error in a claim that doesn't change meaning, or correcting an error in a drawing reference. A CofC cannot be used to change claim scope. A reissue application is required to change claim scope (broaden or narrow claims), correct substantive errors in the specification that affect patentability, or add or remove claims. The practical rule: minor clerical errors → CofC; changes to claim scope or substantive specification corrections → reissue.
What happens to intervening rights in a reissue?
A party who, in good faith, began manufacturing, using, or selling a product before the reissue application was filed may have 'intervening rights' that protect their activities from infringement liability under the broader reissue claims. Under 35 U.S.C. § 252, there are two types of intervening rights: absolute intervening rights (protecting any specific products made or used before the reissue grant) and equitable intervening rights (broader protection based on investments made in reliance on the original, narrower patent). These protections exist to prevent unfair prejudice to parties who were not infringing the original patent but would infringe the broadened reissue claims.