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Certificates Of Correction Of Inventorship Issued After Final Written Decisions May Not Impact The Decisions
04/23/2026On March 9, 2026, the U.S. Court of Appeals for the Federal Circuit (“CAFC”) affirmed an appeal from a Patent Trial and Appeal Board’s (“Board”) final written decision (“FWD”) on remand in an inter partes review (“IPR”), relating to certificates of correction of inventorship issued after the FWDs had been rendered. Implicit, LLC v. Sonos, Inc., No. 2020-1173, ---F.4th--- (Fed. Cir. Mar. 9, 2026). The CAFC affirmed the Board’s holding that certificates of correction issued after the FWDs had been rendered in the respective IPRs had no impact on the FWDs.
Patentee-Appellant owns U.S. Patent Nos. 7,391,791 (the “’791 patent”) and 8,942,252 (the “’252 patent”). Both patents originally listed Edward Balassanian and Scott Bradley as the only co-inventors. Appellee petitioned for an IPR of both patents, asserting unpatentability under 35 U.S.C. §§ 102 and 103. Appellee relied on prior art reference U.S. Patent No. 7,269,338 (“Janevski”), which predated both the ’791 patent and the ’252 patent. Patentee-Appellant argued that Janevski did not constitute prior art because Balassanian and Bradley conceived of the inventions, and worked with engineer Guy Carpenter for implementation, prior to Janevski’s filing date, i.e., Carpenter’s work inured to the inventors’ benefit because the inventions were conceived and actually reduced to practice prior to Janevski’s filing date.
The Board, nevertheless, found that Patentee-Appellant’s evidence was insufficient to establish the conception and communication of the invention to Carpenter needed in order for the reduction to practice to inure the inventors’ benefit. As a result, the Board determined that Janevski constituted prior art, and that it anticipated the challenged claims of both the ’791 patent and ’252 patent under § 102 or made them obvious under § 103.
Patentee-Appellant appealed. For a limited purpose and for issues unrelated to the merits of the case, the CAFC vacated the Board’s decision and remanded. While on remand, Patentee-Appellant requested a 35 U.S.C. § 256 correction of inventorship for both the ’791 patent and the ’252 patent in order to add Carpenter as an inventor on both patents. The Board again ruled against Patentee-Appellant, and the case subsequently returned to the CAFC, but was yet again remanded after the certificates of correction were issued. This time the case was remanded “for the sole purpose of having the [Board] issue an order addressing what, if any, impact the certificates of correction would have on the final written decisions.” On remand, the Board determined that, while § 256 is generally retroactive, “judicial estoppel and waiver appl[ied] under the specific circumstances.” The Board then concluded that Patentee-Appellant was precluded from relying on the certificates of correction of inventorship in the IPR proceedings as a basis to revisit the FWDs.
On this third appeal, Patentee-Appellant contended that: (1) § 256 corrections have a retroactive effect; thus, equitable doctrines such as judicial estoppel, waiver, and forfeiture should not apply to nullify the effect of that correction; and (2) its case does not meet the substantive requirements of judicial estoppel, waiver, or forfeiture and the Board erred in applying such doctrines in its decision.
First, the CAFC addressed whether forfeiture applies in cases where a § 256 correction had been issued. It held that forfeiture could apply to Patentee-Appellant’s antedating argument, despite § 256 corrections, as the Board merely decided that Implicit could not make new antedating arguments based on the correction of invention. The CAFC explained that Patentee-Appellant had not performed the required diligence that was needed to seek correction of inventorship because it “had the opportunity to seek correction of inventorship and assert its change of inventorship theory earlier in the proceeding, and such a change could ‘directly affect the trial and outcome of the proceeding.’”
Second, the CAFC addressed whether the Board abused its discretion in determining that Patentee-Appellant forfeited its ability to argue a new antedating argument based on § 256 corrections. The CAFC held that the Board did not abuse its discretion, as Patentee-Appellant forfeited its right to argue that Carpenter was an inventor to support its antedating argument. The CAFC explained that “[f]orfeiture is the failure to make the timely assertion of a right.” It further found that no change in claim scope occurred in the case and that, from the beginning, Patentee-Appellant had in its sole possession the evidence of inventorship and intentionally presented evidence asserting a certain inventorship—Balassanian and Bradley, without Carpenter.
The CAFC affirmed the Board’s decision—certificates of correction of inventorship issued after the final written decisions had been issued in the respective IPRs had no impact on the final written decisions—holding that forfeiture can apply notwithstanding the retroactive effect of § 256 and that the Board did not abuse its discretion in applying forfeiture to the circumstances of this case. The CAFC stated that it need not reach the arguments regarding judicial estoppel or waiver because forfeiture was an independent ground for affirmance.
