Courts around the country continue to disagree on the causation
standard to be applied in False Claims Act cases based on alleged
Anti-Kickback Statute violations. Two recent federal district court
decisions out of the District of Massachusetts add to differing
conclusions on what the causation standard should be, i.e.,
"but-for," "exposure," or some other, less
demanding standard. In United States v. Regeneron Pharms.,
Inc., No. 20-11217-FDS, 2023 WL 7016900 (D. Mass. Oct. 25,
2023), the district court adopted the Sixth and Eighth
Circuits' "but for" causation standard. See
United States ex rel. Martin v. Hathaway, 63 F.4th 1043 (6th
Cir. 2023), and United States ex rel. Cairns v. D.S. Med.
LLC, 42 F.4th 828 (8th Cir. 2022). In United States v.
Teva Pharmaceuticals USA, Inc., No. 20-11548-NMG, 2023 WL
4565105 (D. Mass. July 14, 2023), a different judge of the same
court adopted the Third Circuit's "exposure"
standard. See United States ex rel. Greenfield v. Medco
