By: Steve Petkovsek

This is first post of a three-part series on patent reissue. Part 2 can be found here. Part 3 can be found here.

Part 1 of this series gives a basic overview of recapture, its statutory basis, and notes some of the changes to the treatment of inequitable conduct post-AIA (America Invents Act). [1]  Part 2 discusses how the court has interpreted limitations such as recapture doctrine and intervening rights. It also covers some general strategies on how to use reissue effectively. Part 3 compares patent reissue to other post-grant proceedings a prosecutor may have in his or her arsenal in both a legal and practical context.



This is Part 1 of a three-part series on patent reissue. It will introduce the reissue statute, discuss some basic uses, and cover some limitations to reissue use. It will also cover post-AIA (America Invents Act) treatment of inequitable conduct in the reissue context. [2]


After a U.S. Patent has issued, the patentee gains legally enforceable exclusive rights as defined by the claims in the patent. However, though the allowed claims enjoy a presumption of validity in subsequent litigation, a patentee should carefully scrutinize his or her patent for defects before attempting to assert those claims via litigation or offers to license. While a patentee surely puts forth the best efforts to find prior art and properly draft a patent during initial prosecution, it is simply cost prohibitive to be absolutely thorough in this regard, particularly since many patents will never be asserted. Furthermore, it is possible that a new understanding of the invention or simply a misunderstanding by the drafting attorney come to light post-issuance, which may result in an improperly defined invention and invalid claims. One method to address these concerns is through patent reissue.

Patent reissue allows the patentee to re-prosecute his or her patent and cure any defects that have been found post-issuance in the claims or specification. This can be done to: gain a presumption of validity over new prior art, correct inconsistencies in claim language, fix inventorship or drawing errors, or broaden or narrow claims. However, there are drawbacks; an owner must admit his or her patent has a defect and the entire patent is reopened for prosecution, not just the desired amendments.  Also, prior to the America Invents Act (AIA), reissue was limited to cases where the patent owner had acted without deceptive intent in prosecution. [3] The AIA eliminated all deceptive intent requirements from the Patent Statute and thus reissue, opening reissue as an avenue to cure prosecution defects even (arguably) if they were a result of admittedly deceptive intent (for example, non-disclosure of known prior art).[4] In this three part series, I will analyze the patent reissue statute, illustrate how subsequent court decisions have interpreted it, and give strategic suggestions on when to use patent reissue instead of other types of post-grant reexamination, such as inter partes and ex parte review.

Patent Reissue Statute: 35 U.S.C. §§251-52

The statutory basis for patent reissue is found in 35 U.S.C. §§251 and 252, the Rules of Practice in 37 CFR §1.171 et seq. and §1.291, and Chapter 1400 of the MPEP.[5] A patent owner has a right to file for a reissuance; the USPTO does not have discretion to reject such a filing if statutory conditions under Section 251 are met. Since reissue is essentially an agreement to re-prosecute an erroneous patent, the same procedures are used as for regular examination under 35 U.S.C. §§132 and 133. The patent owner can also appeal under 35 U.S.C. §134 or seek court review under 35 U.S.C. §§141-145. Protest by third parties is still allowed under 37 C.F.R. § 1.291, and a third party can submit a protest but, unlike other forms of reexamination, a third party has no right to participate in consideration or appeal decisions made by the USPTO during reissue.

Section 251 describes when patent reissue is appropriate. First, it describes what kinds of errors are correctable with reissue proceedings.  Also, a patentee may request several reissued patents for distinct and separate parts of the thing patented.  However, claims in any reissued patent must be directed toward the same invention as the original patent, and some indication must exist in the original patent specification that the patentee considered the subject matter claimed in the reissue patent application to be his or her invention.[6] This is a factual inquiry confined to objective intent manifested by the original patent.[7]  Merely finding that the subject matter was not an object of the original patent, not in the drawings, or not claimed is not sufficient for rejection under the “original patent” clause of Section251.[8] A person having ordinary skill in the art (PHOSITA) must determine that the disclosure of the original patent was an insufficient basis for the new claims absent a showing of intent by the patentee to otherwise narrow the invention. Additionally, Section 251 allows either the inventors or the assignee of the entire interest to file for reissue, but if the application seeks to enlarge the scope of the claims of the original patent, the reissue must be filed in the name of the inventors only. This is because only the inventors can declare a broader concept to actually be their invention.  The reissue application must contain the entire original patent with changes notated properly and claims appropriately numbered.[9] Each claim amendment must have an explanation supporting it. Last, 35 U.S.C. §251 only allows the broadening of claims of the original patent within two years of its issuance.

Only certain types of errors in a patent are correctable under Section 251, and the USPTO has required strict adherence to the literal wording of the statute in this regard.[10] Section 251 requires that:

“the patent, through error, [be] deemed wholly or partly inoperative or invalid by reason of a defective specification or drawing or by the patentee claiming more or less than he had a right to claim.”[11]

Thus, errors must be substantive in nature. The most common reason to reissue is to amend claims. This may be necessary when additional prior art is discovered, prior art is misunderstood, a claim is ambiguous and difficult to enforce, a claim reads upon an excessive number of inoperative embodiments, the invention scope is misunderstood by a drafting attorney, an element of the invention is missing from the claims, or other errors of this sort.[12] Other common errors which can be corrected via reissue are inaccuracies discovered in the disclosure (such as a mistake in the specification or drawings), a mistake or failure in claiming foreign priority or priority of an earlier filed U.S. application, or a mistake regarding inventorship. In essence, reissue was designed to give patentees some maneuverability if a mistake was made in good faith while drafting the patent which went overlooked by the examiner and patentee. Furthermore, the changes made to reissue by the AIA have increased the utility of reissue.

Not all errors which render a patent invalid can be corrected via reissue. This includes errors that could not be corrected in the original patent application, such as a lack of enablement, improper derivation, or a failure to disclose and claim 35 U.S.C. §101 patentable subject matter. Reissue cannot be used to simply reword claims which have the same scope as the originals; the change must be substantive. Procedural mistakes made during prosecution are also beyond the scope of reissue. For example, a failure to file a divisional application directed to nonelected claims has been repeatedly held not to be correctable by reissue.[13]

Finally, post AIA, the patentee no longer needs to declare in the accompanying oath that the error occurred without deceptive intent.[14] The oath still requires sound reasoning for filing a reissuance, i.e. that the patentee believes the original patent to be wholly or partially inoperative for a correctable reason, but no justification must be given as to why the error arose. This opens the door for a more strategic use of reissue without worrying about accusations of inequitable conduct.  Inequitable conduct, which remains a defense against patent infringement, has been defined as a failure to submit known prior art, a failure to explain references in a foreign language, misstatements of fact, and mis-description of inventorship.[15] Inequitable conduct was recently made harder to show in Therasense, Inc. v. Becton, Dickinson & Co., and now must be established as but-for materiality as to the patentability of the application.[16] A patent owner may now admit a defect in a patent that would have previously been an admission of inequitable conduct, which in this case was including an omitted prior art reference. However, since the reference is considered in reissue, according to Therasesne, the previous omission is not but-for materiality if the claims in question survive reissue.[17] The Federal Circuit has not addressed other kinds of inequitable conduct yet, so it is wise to avoid attempting to cure such defects with reissue until a ruling has been made. Until then, a better choice might be supplemental examination.[18]

The purpose and statutory limitations of patent reissue are fairly straightforward. However, as the court has interpreted these rules, it has imposed other limits. Part 2 will discuss how the court has interpreted limitations such as recapture doctrine and intervening rights.



[1] Leahy-Smith America Invents Act, Pub. L. No. 112–29, 125 Stat. 28.

[2] Id.

[3] Id.

[4] Id.

[5] Emery, David P., Reissue and Reexamination of Patents, 15-3 (2008).

[6] Id..

[7] In re Amos, 953 F.2d 613, 618, 21 USPQ2d 1271, 1274 (Fed. Cir. 1991) (quoting In re Rowand, 526 F.2d 558, 560, 187 USPQ 487, 489 (CCPA 1975)).

[8] MPEP §1412.01.

[9] See 37 C.F.R. § 1.173(b).

[10] Emery at 15-4.

[11] 35 U.S.C. § 251(a).

[12] Emery, David P., Reissue and Reexamination of Patents, 15-5 (2008).

[13] MPEP § 1412.01 I.

[14] See 37 C.F.R. § 1.175.

[15] Matlis, Naphtali Y., Reissue v. Supplemental Examination (2014),

[16] See Therasense, Inc. v. Becton, Dickinson & Co., 99 U.S.P.Q.2d 1065 (Fed. Cir. 2011).

[17] Matlis, Naphtali Y., Reissue v. Supplemental Examination (2014),

[18] See Reissue v. Reexamination, supra at 11.