Claim Amendment

A claim amendment is a formal modification to one or more patent claims made during examination before the USPTO. Amendments are typically made in response to office actions — when an examiner rejects claims as anticipated (§ 102), obvious (§ 103), lacking written description or enablement (§ 112), or directed to patent-ineligible subject matter (§ 101). An amendment may: (1) ADD limitations to a claim (narrowing amendment) — adding an element to distinguish from prior art; (2) REMOVE limitations (potentially broadening amendment) — rarely permitted, subject to strict rules; (3) REPLACE claim language with different language; (4) CANCEL a claim entirely; (5) ADD new claims (subject to the no-new-matter rule). The complete history of all amendments and arguments made during prosecution — the 'prosecution history' or 'file wrapper' — is publicly accessible and can affect the scope of the issued patent through prosecution history estoppel.

Under 35 U.S.C. § 132, no amendment shall introduce new matter into the disclosure of the invention. This means: (1) ALL claim amendments must be supported by the original disclosure (specification, claims, and drawings as filed); (2) An applicant cannot add a feature to a claim that was not described in the original application — this would broaden the effective scope of the disclosure without proper examination; (3) New matter rejections under § 132 are distinct from written description rejections under § 112(a) — both address support, but § 132 prevents adding new subject matter through amendment while § 112(a) challenges whether the original application adequately describes the claimed invention. How to add new subject matter: file a continuation-in-part (CIP) application that adds new disclosure — but the new matter will only receive the CIP's filing date as priority, not the parent's date. The no-new-matter rule applies to all amendments: claim amendments, specification amendments, and drawing amendments.

When an applicant narrows a claim by amendment to overcome a prior art rejection (§ 102 or § 103), prosecution history estoppel (also called file wrapper estoppel) prevents the patent owner from later using the doctrine of equivalents to recapture the scope surrendered by the amendment. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (S.Ct. 2002): A narrowing amendment related to patentability creates a PRESUMPTION that the entire territory between the original claim language and the narrowed claim language was surrendered — the patent owner cannot use DOE to cover the surrendered scope. Rebutting the presumption: the patent owner can rebut the Festo presumption by showing: (1) the equivalent was unforeseeable at the time of amendment; (2) the rationale for the amendment bears only a tangential relation to the equivalent; (3) there is some other reason making it unforeseeable that the claim language would be interpreted to encompass the equivalent. Argument-based estoppel: even without an amendment, if the applicant made arguments limiting claim scope to overcome a rejection, prosecution history estoppel can bar DOE for the argued-away scope.

Generally no — claims can only be broadened through broadening reissue within a strict time window. BROADENING REISSUE (35 U.S.C. § 251): An issued patent can be reissued to correct an error in the original patent. Claims may be broadened by reissue ONLY if: (1) Application for broadening reissue is filed within 2 YEARS of the original patent's grant date; (2) The broadened claims are fully supported by the original disclosure (no new matter); (3) The applicant establishes the original patent claims were made 'through error' — an honest mistake, not a deliberate claim scope decision; (4) The broadened claims were not deliberately omitted from the original application. INTERVENING RIGHTS: parties who practice the claimed invention during the period between the original patent's grant and the broadening reissue have intervening rights — they are protected from infringement liability for activities during that period and may have the right to continue those activities. OUTSIDE THE 2-YEAR WINDOW: claims cannot be broadened; only narrowing amendments are permitted after 2 years. By statute, the 2-year window for broadening reissue is absolute.

After a 'Final' office action, the applicant's options for amending claims are limited: AFTER-FINAL CLAIM AMENDMENTS: amendments after a final rejection are not automatically entered; the applicant must request entry, and the examiner has discretion to accept or refuse. After-Final Consideration Pilot (AFCP 2.0): the examiner may consider a non-broadening after-final amendment if it can be resolved without searching new prior art (3 hours of additional examiner work, no fee). Amendments that raise new issues or require new searching are typically refused entry. REQUEST FOR CONTINUED EXAMINATION (RCE) — 37 C.F.R. § 1.114: if an amendment is not entered after final or if further prosecution is needed, the applicant files an RCE (with a fee: $1,800 large entity, $900 small entity for the first RCE), which reopens prosecution — the application is no longer 'final' and further amendments can be freely made. RCE consequences: (1) Consumes patent term adjustment (PTA) — the C-delay rule counts RCE-related delays against PTA; (2) The patent term does NOT restart — it continues running from the original filing date; (3) Multiple RCEs are common in complex cases.