Administrative patent revocation in the US is poised to enter a new period of efficiency, though ironically it will be an efficiency that the America Invents Act originally put in place. The Court's recent approval of the constitutionality of Patent Trial and Appeal Board (" PTAB") proceedings was blunted by the Court's accompanying rejection of partial institution. This Patent Office practice of accepting and denying validity review petitions piecemeal had been a key part of the agency's procedural structure from the start. As a result, the Court's decision in SAS Institute v. Iancu to require a binary choice-either fully accepting a PTAB petition or fully denying it-is already being criticized for sacrificing efficiency on the altar of wooden statutory interpretation, including two dissents from the decision itself Starting from the premise that SAS Institute was rightly decided, however, this paper makes two contributions. The theoretical contribution is to contrast PTAB estoppel with ordinary principles of res judicata and collateral estoppel. This important context is lacking in the literature, and the profound effect of SAS Institute on PTAB estoppel makes this evaluation especially timely. The empirical contribution is to marshal new data and guide the difficult structural choices that the agency must now make in order to comply with SAS Institute. Notably, though justice Ginsburg's dissent suggested that the agency could comply with the Court's decision through afew empty gestures, her mock proposal is actually a sound plan of action. By reinvigorating Congress's view of efficiency, one that is more systemic than merely minimizing short-term agency workload, the Court has enabled the Patent Office to resolve open questions about the maturing