Terminal Disclaimer

Obviousness-type Double Patenting (ODP)

• A non-statutory rejection (not based on a specific code section but on equitable principles) that prevents a patent applicant from extending their patent monopoly by claiming obvious variants of the same invention in multiple related applications
• The USPTO issues ODP rejections when claims in a continuation, divisional, or CIP application are 'obvious variants' of claims in a parent application or another family member

By Filing a Terminal Disclaimer

• The applicant agrees that the later application (the 'disclaimed' patent) will expire no later than the expiration date of the earlier reference patent
• The applications must remain commonly owned
• The ODP rejection is overcome because extending the monopoly is prevented

Form

• The terminal disclaimer is filed on USPTO Form PTO/AIA/25 (for AIA applications)
• It must specifically identify the reference patent or application

When not Required

• (1) if the claims in the continuation are patentably distinct from the parent's claims (no ODP rejection), no terminal disclaimer is needed
• (2) if the ODP rejection can be overcome by argument (the claims are not obvious variants), argument alone is an alternative

The Requirement

• A terminal disclaimer typically includes a covenant that the disclaimed patent shall be enforceable only during such time as it and the reference patent (the one it disclaims over) are commonly owned
• 37 C.F.R. § 1.321(c)

What 'Commonly Owned' Means

• All rights to the disclaimed patent AND the reference patent must be held by the same person or entity at all times
• This includes situations where: (1) the same assignee holds both patents
• (2) the patents are licensed exclusively to the same entity (depending on rights transferred)

Practical Implication

• If a company sells or assigns the disclaimed patent to one party while another party retains the reference patent, the disclaimed patent becomes unenforceable
• This creates significant problems in patent portfolio transactions, mergers, acquisitions, and licensing

Due Diligence in Transactions

• When acquiring a patent that has a terminal disclaimer, the acquiring party must: (a) identify what patent it disclaims over
• (b) ensure the reference patent is also acquired or will remain commonly owned
• (c) if the reference patent has expired or been invalidated, the terminal disclaimer relationship may affect enforceability

Terminal Disclaimer Chain

• Multiple continuations in a family may each have terminal disclaimers over the parent, creating a chain
• If the parent is invalidated, the terminal disclaimer relationship can affect the entire chain's enforceability
• ALLERGAN v. MSN (Fed. Cir. 2025): raised new questions about whether a terminal disclaimer over an earlier-expiring reference patent affects the disclaimed patent's enforceability when the reference patent has been invalidated.

Basic Term Effect

• The disclaimed patent's term is limited to the EARLIER of: (a) 20 years from its earliest effective US filing date + PTA
• Or (b) the expiration date of the reference patent (also considering that patent's own PTA and any terminal disclaimers it may have)

Example

• Parent Patent expires June 1, 2035
• Continuation Patent has a base term of June 1, 2038 (filed later)
• Continuation files a terminal disclaimer over Parent
• Continuation's enforceable term = June 1, 2035 (matches Parent)
• The 3 additional years from the later filing date are surrendered

Patent Term Adjustment (PTA) Interaction

• Before 2025, a continuation patent that filed a terminal disclaimer could still accumulate PTA for USPTO delays, potentially extending its term beyond the reference patent's term IF the PTA pushed it past the reference patent's expiration + its own PTA
• 2025 USPTO RULE CHANGES (effective May 2025): the USPTO enacted regulations significantly restricting PTA accumulation for patents with terminal disclaimers
• The 2025 rules prevent terminal-disclaimed patents from accumulating PTA beyond the reference patent's base expiration date
• This effectively eliminates a strategy of accumulating PTA on continuation applications to gain additional term beyond the parent

Statutory Double Patenting (SDP)

• Based on 35 U.S.C. § 101 ('a patent' — singular)
• The exact same invention cannot be patented twice
• SDP occurs when claims in a second application are IDENTICAL to claims in a first patent (same claims, same inventor or assignee)
• SDP CANNOT be overcome by a terminal disclaimer — the claims must be differentiated
• SDP is rarely at issue because applicants typically draft different claims across applications

Obviousness-type Double Patenting (ODP)

• A non-statutory rejection based on equitable principles
• The claims in the second application are not identical but are obvious in view of the first patent's claims
• ODP prevents applicants from extending patent protection by claiming obvious variants
• CAN be overcome by a terminal disclaimer
• Most common form of double patenting in practice

ODP Obviousness Test

• The ODP analysis evaluates whether the claim differences between the two applications are obvious to a person of ordinary skill in the art
• This is similar to, but distinct from, the prior art obviousness analysis under § 103
• ODP uses a different analysis than § 103 because it compares CLAIMS rather than claims vs. prior art

Argument to Overcome ODP

• An applicant can argue that the claims are patentably distinct (not obvious variants) as an alternative to filing a terminal disclaimer
• If the claims are genuinely different, argument alone is preferable because it preserves full patent term

Withdrawal is Generally not Possible

• Once a terminal disclaimer is filed and the patent issues, the disclaimer is part of the patent and cannot be withdrawn
• There is no USPTO procedure to remove a terminal disclaimer after issuance
• The patentee made a permanent election to limit the patent term

Arguing Against ODP Before Filing

• The best approach is to argue the ODP rejection before filing a terminal disclaimer
• Draft continuation claims that are patentably distinct from the parent's claims
• Argue that specific limitations in the continuation claims make them non-obvious over the parent's claims
• If the argument succeeds, no terminal disclaimer is required

Cost-benefit Analysis Before Filing

• If ODP rejection is issued, the applicant should consider: (a) does the continuation add sufficient new claim scope to justify the term limitation?
• (b) is the term limitation from the terminal disclaimer acceptable given the patent's commercial importance?
• (c) can the ODP rejection be overcome by claim amendment rather than terminal disclaimer?

Divisional Application Exemption

• A divisional application is generally not subject to ODP because the patent office itself required the restriction — forcing the applicant to file a divisional rather than including all claims in one application
• This is called the 'safe harbor' for divisionals
• Note: this exemption applies to RESTRICTIONS required by the USPTO, not voluntary divisionals filed without a restriction requirement