On July 2008, MPEP §1402 was revised to state:

“An error under 35 U.S.C. 251 has not been presented where a reissue application only adds one or more claims that is/are narrower than one or more broader existing patent claims without either narrowing the broader patent claim by amendment or canceling the broader patent claim. A reissue application in which the only error specified to support reissue is the failure to include one or more claims that is/are narrower than at least one of the existing patent claim(s) without an allegation that one or more of the broader patent claim(s) is/are too broad together with an amendment to such claim(s), does not meet the requirements of 35 U.S.C. 251. Such a reissue application should not be allowed.”

On April 15, 2011, however, the Federal Circuit held that patent applicants can file a reissue application that retains all original claims and adds only dependent claims. In re Yasuhito Tanaka (Fed. Cir., April 15, 2011). The Federal Circuit held that §251 provides “[w]henever any patent is… deemed wholly or partly inoperative or invalid… by reason of the patentee claiming more or less than he had a right to claim in the patent, the Director shall…reissue the patent…” Relying on precedent, the Federal Circuit noted that the term “less” means including fewer claims in the application than the patentee could have properly included rather than referring to claiming a narrower scope of protection than the patentee was entitled to claim. Accordingly, the Federal Circuit held that patent applicants can file a reissue application for purposes of adding only additional dependent claims.

Based on the Court’s ruling in In re Tanaka, in August 2011, the U.S. Patent and Trademark Office (USPTO) implemented a new policy:

“Where the only change to a patent made in an application for its reissue is the addition of a claim or claims that is/are narrower in scope than the existing patent claims, without any narrowing of the existing patent claims, the application claims are not to be rejected as failing to state an error under 35 U.S.C. §251. In addition, any rejection of record in a pending application on this basis will be withdrawn, and any new Office action issued will inform applicant of the withdrawal, and the resulting status of the application in view of the withdrawal.”