U.S. Supreme Court has held that the non-appealability of Patent Trial and Appeal Board (PTAB) institution decisions encompasses PTAB decisions on whether a statutory time bar applies. And that specifically, 35 U.S.C. §314(d), which sets forth the finality and nonappealability of decisions on the institution of an Inter Partes Review (IPR) proceeding “under this section,” includes decisions implicating the one-year time bar under 35 U.S.C. §315(b). The background on the case and full analysis of the holding is available here.