This case comes to us on remand from the Supreme Court, which vacated our earlier opinion reversing the district court’s judgment that certain claims were not indefinite (Group I claims), and affirming the district court’s holdings that other claims (Group II claims) were valid and infringed.2 Teva Pharm. USA, Inc. v. Sandoz, Inc., 723 F.3d 1363 (Fed. Cir. 2013), vacated, Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (2015). Relevant to the Group I claims, the Supreme Court held that the ultimate construction of a claim term is a question of law, subject to de novo review, and that underlying subsidiary fact findings are subject to clear error review. Teva, 135 S. Ct. at 837–38, 841–42. During that same time, the Supreme Court issued its opinion in Nautilus, Inc. v. Biosig Instruments, Inc. (Nautilus II), 134 S. Ct. 2120 (2014), addressing the standard for indefiniteness. On remand, the parties submitted supplemental briefing explaining how the appeal should be resolved in light of the Supreme Court’s Teva decision. See Teva Pharm. USA, Inc. v. Sandoz, Inc., No. 12-1567 (Fed. Cir. Feb. 20, 2015), ECF No. 137. Applying the legal standards set forth in the Supreme Court’s Teva and Nautilus II decisions, we hold that the Group I claims are invalid for indefiniteness.