Terminal disclaimer (TD)

A proper terminal disclaimer must disclaim the terminal part of the statutory term of any patent granted on the application being examined that would extend beyond the expiration date of the full statutory term, shortened by any terminal disclaimer, of the patent that is the basis of the nonstatutory double patenting¹. It must operate with respect to all claims in the patent².

Under 37 CFR 1.321(b), a terminal disclaimer filed in an application is binding upon the grantee and its successors or assigns. To be recorded it must be signed by the applicant or an attorney or agent of record, specify the portion of the term being disclaimed, state the applicant's present ownership interest in the patent to be granted, and be accompanied by the fee³.

The MPEP gives public-interest reasons for accepting one: it encourages the disclosure of additional developments, the earlier filing of applications and the earlier expiration of patents, so the inventions become freely available to the public².

A terminal disclaimer filed to obviate judicially created double patenting must include a provision that any patent granted on the application is enforceable only for and during the period that it is commonly owned with the application or patent that formed the basis for the double patenting (37 CFR 1.321(c)(3))³. The MPEP says common ownership is judged at the time of enforcement¹.

• If several conflicting patents or applications are applied in double patenting rejections, each commonly owned reference must be included in the terminal disclaimer, so that a split in ownership with any one of them is covered².
• Where the reference is not commonly owned but was disqualified as prior art because of a joint research agreement, 37 CFR 1.321(d) instead requires a waiver of the right to separately enforce the two patents³.
• A terminal disclaimer is effective only for the application identified in it, unless by its terms it extends to continuing applications. One filed in a parent normally has no effect on a continuing application^1,2. See Continuation application.

• It is not effective in overcoming a statutory double patenting rejection, which concerns the same invention claimed twice².
• It cannot be used to overcome a prior art rejection under 35 U.S.C. 102 or 103².
• A terminal disclaimer filed after the reference patent has expired is not effective to obviate a nonstatutory double patenting rejection (Boehringer Ingelheim v. Barr Laboratories, Fed. Cir. 2010)^1,2.
• A request for a common issue date cannot substitute for a terminal disclaimer when the rejection is proper².
• Filing one is not an admission that the rejection was correct: it removes the rejection and raises neither a presumption nor an estoppel on its merits (Quad Environmental Technologies v. Union Sanitary District, Fed. Cir. 1991)².

A terminal disclaimer may also affect patent term adjustment: under 35 U.S.C. 154(b)(2)(B), no patent whose term has been disclaimed beyond a specified date may be adjusted beyond the expiration date in the disclaimer¹. The Federal Circuit held in In re Cellect (2023) that obviousness-type double patenting for a patent that has received patent term adjustment (PTA) must be based on its expiration date after PTA is added, whether or not a terminal disclaimer is required or has been filed⁶. A terminal disclaimer filed to overcome such a rejection can therefore remove the PTA beyond the reference patent's expiry^1,6. See Patent term adjustment.

A recorded terminal disclaimer may be withdrawn by petition under 37 CFR 1.182 only before the application issues as a patent. After issuance it will not be nullified, and certificates of correction, reissue, reexamination, inter partes review and post grant review are not available to do so¹.

On May 10, 2024 the USPTO published a proposed rule (89 FR 40439) to add a new requirement for an acceptable terminal disclaimer filed to obviate nonstatutory double patenting. The disclaimant would have agreed that the patent is enforceable only if it is not, and has never been, tied directly or indirectly by terminal disclaimers to a patent in which any claim was finally held unpatentable or invalid as anticipated or obvious by a Federal court or by the USPTO, with all appeal rights exhausted, or in which a claim was statutorily disclaimed after an anticipation or obviousness challenge⁴.

The USPTO withdrew that proposal. The Federal Register notice of December 4, 2024 states that the proposed rule is withdrawn as of December 4, 2024, and that the agency decided not to move forward at this time, citing resource constraints, after receiving more than 300 comments⁵. The proposal was never added to the rule: 37 CFR 1.321(c) continues to contain the requirements described above³.