On August 28, 2026, the Federal Circuit issued a precedential opinion in T-Mobile US, Inc. v. KAIFI LLC, No. 2025-1006 (Taranto, Schall, and Chen, JJ., opinion by Chen). The appellants are T-Mobile US, Inc. and T-Mobile USA, Inc. The court did not decide whether T-Mobile owes the contingent reexamination payment. It held that it lacks appellate jurisdiction and transferred the case to the Fifth Circuit.

The deal, and the fight over "survives"

KAIFI sued T-Mobile for infringement of U.S. Patent 6,922,728, directed to Wi-Fi calling, in the Eastern District of Texas on August 28, 2020, in No. 2:20-cv-00281. T-Mobile requested ex parte reexamination. Days before trial, on January 12, 2022, the parties settled that case under Texas law. T-Mobile took a license, paid an upfront amount, and agreed to an additional "EPR Payment" if any Asserted Claim "survives the EPR." The asserted claims were 1, 2, 3, 5, 7, 10, 11, and 20. The Office later confirmed claims 1, 2, 3, 5, 10, 11, and 20 patentable without amendment; claim 7 was patentable as amended. T-Mobile refused the extra payment and filed a later declaratory-judgment action, No. 2:22-cv-00192-JRG (Gilstrap), in which T-Mobile US, Inc. and T-Mobile USA, Inc. sought a declaration that no asserted claim survived. KAIFI counterclaimed for breach. Judge Gilstrap granted summary judgment for KAIFI and ordered the payment, reading "survives" to mean confirmed as patentable in the reexamination certificate.

The holding

Federal Circuit jurisdiction under 28 U.S.C. 1295(a)(1) reaches cases arising under the patent laws. A Texas-law contract claim gets there only if it necessarily raises a substantial patent-law issue under Gunn v. Minton. This one does not. Interpreting "survives the EPR" is contract construction. The August 28 opinion noted that the '728 patent had expired and that no other litigation on it was pending; those circumstances informed the court's substantiality analysis. The court transferred the appeal to the Fifth Circuit, which has appellate jurisdiction over the Eastern District of Texas. The parties bear their own costs.

What it means in practice

Settlement clauses that turn on reexamination, IPR, or "surviving" claims will often be state-law contract fights, even when the trigger is a Patent Office outcome. Do not assume the Federal Circuit is the reviewing court. Draft the trigger in the agreement; do not leave "survives" to post-hoc claim-scope arguments. The opinion left the payment merits for the transferred appeal.

What to watch next

Watch the Fifth Circuit's construction of "survives the EPR" on the transferred appeal, and whether later settlement agreements start defining that phrase on the face of the contract.