Rethinking Equitable Estoppel in Patent Law

Lustig, Joshua J | October 1, 2022

In almost every context, the Federal Circuit has used estoppel doctrines to provide protection to parties from some sort of injustice. Yet recently, with equitable estoppel, the Federal Circuit has decided to infuse concepts of Article III justiciability to justify limiting the doctrine as only applicable to issued patents. In doing so, the Federal Circuit has ignored the long history behind equitable estoppel in favor of a rule that is improperly rationalized by the Constitution. This note argues that Federal Circuit’s recent equitable estoppel jurisprudence is inconsistent with equity’s goal of fairness and presents a new theory of equitable estoppel — “inchoate estoppel” — which would create fairer outcomes for patentees and defendants alike.