In a significant precedential development, two federal circuit courts have imposed strict causation requirements in health care kickback cases under the Federal False Claims Act (FCA), placing under duress one of the go-to bases for such suits. At the heart of the development is a question about the meaning of a 2010 legislative change, when Congress said that the FCA applies to claims for items or services "resulting from" illegal remuneration paid for health care referrals in violation of the Anti-Kickback Statute (AKS).