On January 9, 2017, the Supreme Court denied certiorari in United States ex rel. Purcell v. MWI Corp., No. 16-361, ending one of the longest running False Claims Act (“FCA”) cases in history. In so doing, the Supreme Court let stand a significant decision by the D.C. Circuit that severely limits FCA liability where the allegations are dependent on violations of ambiguous agency regulations. See United States ex rel. Purcell v. MWI Corp., 807 F.3d 281 (D.C. Cir. 2015).