Patent Disclaimer

A patent disclaimer is a formal statement by a patent owner or applicant to the USPTO surrendering a portion of their patent rights. Under 35 U.S.C. § 253, there are two principal types: (1) STATUTORY DISCLAIMER OF CLAIMS (§ 253(a)): the patent owner may disclaim one or more complete claims of the patent; the disclaimed claims are treated as if they never existed; once filed, the disclaimer is IRREVOCABLE — the patent owner cannot later reclaim the disclaimed claims; this is used when: a claim is found invalid in litigation and the patent owner wants to protect the remaining claims from being invalidated as well; a claim is overly broad and the patent owner voluntarily narrows the patent; the patent owner wants to simplify the patent for licensing or enforcement purposes; (2) TERMINAL DISCLAIMER (§ 253(b)) — DISCLAIMER OF PATENT TERM: the patent owner disclaims the terminal portion of the patent term — i.e., the portion of the term that extends beyond a specific date; most commonly used to overcome an obviousness-type double patenting (ODP) rejection during prosecution; the terminal disclaimer makes the entire family of terminally disclaimed patents expire on the same date (co-terminus), and requires the patents to remain under common ownership at all times; this is the most common type of disclaimer encountered in USPTO prosecution. EFFECT ON ENFORCEMENT: a disclaimed claim cannot be asserted in litigation; it is not subject to maintenance fees and does not contribute to patent term; once a statutory disclaimer is filed, it is published in the Official Gazette.

A terminal disclaimer (TD) is a statement by the patent applicant or owner that the patent — or a portion of the patent term — is surrendered so that the patent will expire on the same date as a related co-pending or issued patent. MOST COMMON USE — OBVIOUSNESS-TYPE DOUBLE PATENTING (ODP): when a patent applicant has two related patents or applications with patentably indistinct claims (claims that are obvious variants of each other), the USPTO will reject the later-filed claims under ODP to prevent a patent owner from effectively extending the patent term on the same invention by filing continuation applications; the applicant can OVERCOME the ODP rejection by filing a terminal disclaimer that: (a) limits the term of the later patent/application to expire on the same date as the earlier patent; (b) requires that the later patent remain in the same ownership as the earlier patent at all times; if co-ownership is ever broken, the later patent becomes unenforceable against the infringer; FEES: PTO/SB/20 form; $200 fee ($100 small entity, $50 micro entity) per terminal disclaimer filed during prosecution; PTA FORFEITURE: when a terminal disclaimer limits the patent term, patent term adjustment (PTA) accumulated due to USPTO delays (under 35 U.S.C. § 154(b)) may be partially forfeited — the patent cannot extend beyond the date to which the term was disclaimed, even if PTA would otherwise add days; EXAMPLE: Patent A issued Jan. 1, 2020 (expires Jan. 1, 2040); Patent B application claims obvious variant; ODP rejection; patent owner files TD making Patent B expire Jan. 1, 2040 (same as Patent A), even if Patent B could otherwise expire later due to a later filing date or PTA.

Terminal disclaimers create a mandatory co-ownership requirement that can be strategically important: THE REQUIREMENT: a terminal disclaimer filed to overcome an ODP rejection must include a statement that the patent (or application) will be enforceable only for and during such time as it is commonly owned with the [patent/application against which ODP was rejected]; WHAT 'COMMONLY OWNED' MEANS: all terminally disclaimed patents must be owned by the same entity (or entities) at all times; if the patents are separately assigned — even temporarily — to different owners, the patent with the terminal disclaimer becomes unenforceable during the period of separate ownership; CO-OWNERSHIP ISSUES IN TRANSACTIONS: in acquisitions, patent portfolios may include terminally disclaimed patents tied to related patents; if the parties are not careful to ensure that ALL patents in a terminally disclaimed chain are conveyed together, enforceability may be lost; JOINT VENTURES AND LICENSING: exclusive licensees of patents in a terminally disclaimed family may face issues if they hold rights to some but not all patents in the family; courts have analyzed whether an exclusive license constitutes 'ownership' for co-ownership purposes in specific cases; PRACTICAL REQUIREMENT: in any patent portfolio due diligence, buyers should identify all terminal disclaimers and ensure that all co-disclaimed patents are being acquired; document that co-ownership will be maintained; PENDENCY IN IPR: in IPR, if a patent with a terminal disclaimer loses co-ownership, the patent owner cannot rely on the disclaimed patent term and may face invalidity arguments related to the ODP that the TD was filed to overcome.

Though both arise under § 253, they serve completely different purposes and have different effects: STATUTORY DISCLAIMER OF CLAIMS: applies to specific individual claims; the disclaimed claims are excised from the patent and treated as never having existed; no effect on the patent term for the remaining claims; typically used AFTER issuance when specific claims are found invalid or are no longer needed; irrevocable — once a claim is disclaimed, it cannot be reasserted; effect on related applications: disclaiming a claim in an issued patent does not automatically disclaim the same claim in a child application, but prosecution history may affect child applications; TERMINAL DISCLAIMER OF PATENT TERM: applies to the terminal portion of the PATENT TERM, not to specific claims; all claims survive (none are excised); the patent simply expires earlier, on the same date as the co-disclaimed patent; requires common ownership as a condition of enforceability; typically used DURING PROSECUTION to overcome ODP rejections; COMMON CONFUSION: practitioners sometimes informally refer to both as 'disclaimers,' but they serve completely different functions; a terminal disclaimer does NOT cancel any claims — it only shortens the patent's life; a statutory disclaimer does NOT affect the term — it cancels specific claims; COMBINATION: it is possible (though unusual) for a patent to have both — a terminal disclaimer affecting the term AND a statutory disclaimer canceling specific claims; this would be documented in the patent's file wrapper.

Yes — terminal disclaimers can have significant consequences in patent litigation that practitioners often overlook: (1) ODP INVALIDITY IF TD IS IMPROPER: a terminal disclaimer, while it overcomes an ODP rejection during prosecution, does not PROVE the claims are patentably distinct; it is simply an administrative cure; in litigation, an accused infringer can still challenge the claims as INVALID for obviousness-type double patenting, arguing the claims are patentably indistinct from the co-owned patent and the TD did not cure the underlying invalidity; after Boehringer Ingelheim Int'l v. Barr Labs (Fed. Cir. 2019), there is ongoing debate about whether a TD is a full cure of ODP or only an administrative acquiescence; (2) CO-OWNERSHIP BREAKS ENFORCEABILITY: as noted above, if the terminally disclaimed patent loses common ownership with the patent/application cited in the TD (even briefly), it may become unenforceable; this is a continuing obligation, not just a filing requirement; (3) TERM LIMITATION AFFECTS DAMAGES WINDOW: a terminal disclaimer that shortens the patent term reduces the window for damages in litigation; claims of infringement can only extend during the actual patent term (after TD); (4) ESTOPPEL ARGUMENTS: a terminal disclaimer, like other prosecution history acts, can create argument estoppel; the act of filing a TD may be used in litigation to argue that the applicant recognized the claims were obvious variants of the co-owned claims, affecting claim construction or DOE arguments.