Strategic Uses and Considerations for Reissue Applications (Part 1 of 3)

Reissue applications represent a very small fraction of the total number of applications filed at the USPTO each year. Indeed, at the midpoint of 2025, over 1.2 million utility applications have been filed, with less than 300 of them being reissue applications. As such, it is not uncommon to speak to a US patent practitioner or patent owner that has never filed a reissue application. This three-part series will provide an overview of strategic uses and considerations for reissue applications to help you identify when pursuing a reissue application may be advantageous.

Part 1: Establishing an Adequate Ground for a Reissue Application

As is evident, to pursue a reissue application successfully, you must first get a reissue application on file. However, the requirements for filing a reissue application differ from the more familiar requirements for filing a continuation application.

A reissue application is a statutorily provided mechanism to correct an error in an unexpired patent. As such, to successfully get a reissue application on file, you must expressly identify an error in an unexpired patent. However, not all errors provide sufficient ground for a reissue application. The identified error must render the patent “wholly or partly inoperative or invalid.” See 35 U.S.C. § 251(a). “Claiming more or less than [one] had a right to claim in the patent” is an error that provides adequate ground for a reissue application, and it is the most common error expressly identified by successful filers of reissue applications.

Some may feel dissuaded from filing a reissue application because of concerns in stating on the record that an issued patent has an error that renders it “wholly or partly inoperative or invalid.” The Federal Circuit has clarified, however, that “the omission of a narrower claim from a patent can render a patent partly inoperative by failing to protect the disclosed invention to the full extent allowed by law.” See In re Tanaka 640 F.3d 1246, 1251 (Fed. Cir. 2011). In other words, the error that renders a patent “wholly or partly inoperative or invalid” —and that provides ground of a reissue application —may simply be the error of not previously including a narrower dependent claim that provides more robust coverage of a species already encompassed by issued claims of the patent. As such, a statement on the record identifying an error that renders a patent “wholly or partly inoperative or invalid” can be quite innocuous.

Many of the strategic uses of reissue applications relate to adjustments to issued claim scope, which may also provide adequate ground for filing a reissue application. Others, however, relate to adjustments that do not alone provide adequate grounds for reissue. To pursue these strategic uses of reissues applications, one can first provide sufficient ground for the reissue application (a la In re Tanaka) by introducing a narrower dependent claim that provides more robust coverage of a species already encompassed by issued claims of the patent (or by identifying another error that renders the patent “wholly or partly inoperative or invalid”).

Part two of this series will cover strategic uses of reissue applications and adjusting claim scope. The series will conclude with additional strategic uses, limitations, and considerations.