Risky Business: Patent Term Adjustment in the Post- Forest Era

What value is a patent that expires before it issues?

Until recently, that question seemed wholly academic. In In re Forest, however, the U.S. Court of Appeals for the Federal Circuit (CAFC) answered it directly: A patent that issues after its expiration date has no value; it provides neither exclusionary rights nor provisional rights. In the court’s view, the applicant has no cognizable interest in the patent or the application on which it would be based.

Today, the U.S. Patent and Trademark Office (USPTO) is asking that question of patent applicants. Following In re Forest, the USPTO has begun to identify applications that cannot issue with any enforceable patent term and, in such applications, to issue orders to show cause why prosecution should continue. For patent practitioners, the implications are significant. Patent Term Adjustment (PTA) can no longer be viewed merely as a bonus that extends patent life. In the post-Forest era, PTA may be the only basis for maintaining a patent application past its 20-year statutory date.

In re Forest

On April 3, 2025, the CAFC dismissed an appeal brought by a Donald Forest after concluding that any patent resulting from his application would expire before issuance.

Under U.S. law, a patent grants the patentee an exclusionary right to preclude others from practicing the patented invention in the U.S for a term beginning when the patent issues and ending 20 years after filing of the earliest-claimed non-provisional priority application, plus any accrued patent term adjustment (PTA) under 35 U.S.C. § 154.[1] A patent grant also confers an additional “provisional right” to obtain a reasonable royalty from any person who practices the invention from the time the patent application is published until the patent issues.

Forest’s patent application was filed more than 21 years after the earliest non-provisional priority date and, thus, would have expired before issuance regardless of any PTA accrued. In the appeal, the USPTO argued that the court lacked jurisdiction because Forest’s application would necessarily grant with zero term and, therefore, he had “no personal stake” in the appeal.

Forest did not dispute that the patent would grant without any exclusionary right. He argued that the plain text of 35 U.S.C. § 154(d) provides that provisional rights attach beginning at publication, and that the section does not make any reference to expiry. Thus, the CAFC was presented with a simple question: Can provisional rights exist when the patent itself would issue without any exclusionary rights?

The CAFC rejected Forest’s argument that provisional rights would still attach, holding that “provisional rights [under 35 U.S.C. § 154(d)] are granted only when a patent would issue with exclusionary rights (i.e., would issue before its expiration date).” As Forest’s prospective patent would have “issued” as an already-expired patent, it could not generate preliminary rights. Because Forest could not obtain any rights from the patent grant, he lacked the necessary personal stake to confer jurisdiction over the appeal.

The USPTO Response to In re Forest

The significance of In re Forest extends beyond the jurisdictional dispute. In June 2026, the USPTO began implementing the decision, publishing a Patent Alert that describes a new procedure to eliminate applications that would issue after expiry. The Patent Alert indicates that the USPTO has begun 1) identifying pending application which, if issued, would result in a patent without any term (with no possibility of accruing Patent Term Adjustment which would result in patent term) and 2) mailing orders to show cause why prosecution of such applications should continue, even though any resulting patent would issue without exclusionary rights.

The USPTO issued an example of such an Order to Show Cause in July 2025 in the Forest application, some four months after the CAFC mandate. The Order to Show Cause set forth the priority benefit claim of the Forest application, calculated the expiry date of the patent that could be granted therefrom to be in the past (notably, without any discussion of PTA or its possible effect on the expiry date calculated), and asserted that any patent issuing from the application would issue without provisional or exclusory rights. The Order to Show Cause provided a period of 30 days for Forest to show why the USPTO should not terminate prosecution.

Per the Patent Alert, applicants in a similar position to Forest should expect to receive a similar order to show cause.

The Hidden Value of PTA

The Forest application presented an easy case—the statutory expiration date had passed when the application was filed. This application was certain to issue without an enforceable patent term. In that circumstance, continued prosecution serves little purpose because any resulting patent would issue without exclusionary rights.

Other late-term applications that have not yet reached their statutory 20-year dates, or that have accrued significant PTA, may still issue with enforceable term even if they issue after the 20-year date. For example, an application receiving two years of PTA will expire 22 years after its earliest-claimed non-provisional priority date. For such applications, issuance even after the 20-year mark can result in patents with meaningful patent terms and accompanying provisional and (perhaps brief) exclusionary rights.

In fact, once an application has passed its statutory 20-year date, the prospect of obtaining sufficient PTA to create an enforceable patent term may be the principal justification for continuing prosecution. Reliance on PTA may be the only persuasive response to an order to show cause. (This article addresses PTA under 35 U.S.C. § 154. Patent Term Extension (PTE) under 35 U.S.C. § 156 may raise distinct issues under Forest, but those issues are beyond the scope of this article.)

The Role of PTA

The significance of PTA in this context extends beyond simply lengthening patent life. For late-term applications, PTA may be better understood as shifting patent term from the prosecution period to the post-issuance period. Rather than simply increasing the length of an already-existing patent term, PTA may supply the enforceable term necessary for patent rights to arise at all.

Continued prosecution after the statutory 20-year date also presents a unique dynamic. While an application remains pending, additional PTA may accrue from qualifying USPTO delays. At the same time, however, the statutory patent term continues to erode as time passes. Thus, continued USPTO delay may simultaneously push both the anticipated issuance date and the anticipated expiration date further into the future. As qualifying USPTO delays generate additional PTA, the patent term is effectively translated forward in time, shifting enforceable rights from the application’s filing date and toward a later post-issuance period.

Consider a hypothetical application that reaches its statutory expiration date with six months of accrued PTA. An applicant may choose to continue prosecution in reliance on that PTA term. During the next year of prosecution, the application may accrue an additional eight months of PTA attributable to USPTO delay. However, because a year has elapsed while the application remained pending, a year of potential post-issuance term has also been consumed. Although the application accumulated eight additional months of PTA, its net remaining patent term has actually decreased from six months to two months. In effect, continued prosecution has shifted what would once have been years of enforceable life near the filing date into a narrow, future two-month period. PTA in this circumstance functions less as a simple extension and more as a mechanism for shifting enforceable patent term into the future.

This dynamic can create unusual results within a patent family. Earlier-issued family members may have already expired based on their ordinary 20-year terms, giving the appearance that the family’s patent coverage has ended. Yet, in the absence of double patenting considerations, a continuation or other related application may remain pending and continue accruing PTA. If that application later issues with sufficient PTA, it may emerge as the only enforceable member of the family despite issuing years after the related patents have expired.

The result may be a period during which no family member is enforceable, followed by the issuance of a patent that restores enforceable rights. What appears to be an expired patent family may, in fact, possess the potential for enforceable rights through a pending application with accrued PTA.

New Considerations

Before Forest and the USPTO’s June 2026 Patent Alert, the length of patent term was an issue practitioners and applicants often considered only after allowance or even after issuance. Given Forest and the USPTO’s response, patent term should not be viewed solely as an issue for allowed or issued patents. For applications nearing the end of their 20-year terms, the amount of patent term remaining at issuance may determine whether the application can mature into a patent at all. Practitioners should carefully consider the likelihood of issuance before expiry for late-filed patent applications, and should estimate the available PTA when considering whether to maintain pendency.

The lesson of Forest and the USPTO’s response is straightforward: Patent term is not merely a post-issuance concern. In the post-Forest era, PTA may determine not only how long a patent remains in force, but also whether the application remains pending.

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