In In re CSB-System Int’l, Inc., No. 15-1832 (Fed. Cir. Aug. 9, 2016), the Federal Circuit held that patents that expire during a pending reexamination should not be examined under the broadest reasonable interpretation (BRI) standard.

CSB’s patent was subjected to an ex parte reexam before it expired. During the pendency of an appeal to the PTAB of the examiner’s rejection of all claims, the patent expired. The PTAB, in analyzing the examiner’s claim constructions, which applied the BRI standard, applied the same standard.

The Federal Circuit held that the PTAB erred in using the same standard. The Court acknowledged that during reexams of unexpired patents the PTAB indeed should use the BRI standard. But when a patent expires during the reexam, the PTAB should thereafter apply the claim construction standard set forth in Phillips v. AWH Corp. The Court rejected the Patent Office’s argument that the PTAB, as a reviewer of the examiner’s work, should review claim constructions consistent with the standard used by the examiner. It held that the Phillips standard applies to expired patents in reexam regardless of the standard that the examiner applied. Nonetheless, it affirmed the PTAB’s decision because applying the BRI standard in this case produced the same result that would have been obtained under the correct Phillips standard.