The Anti-Kickback Statute (AKS) is a criminal law that prohibits offering or receiving anything of value to induce referrals for services covered by federal healthcare programs. It applies to all healthcare providers and requires proof of intent.
The Stark Law is a civil statute that applies only to physicians. It prohibits self-referrals for certain designated health services to entities with which the physician or a family member has a financial relationship—regardless of intent.
In short, AKS focuses on intentional kickbacks across the industry, while Stark targets physician self-referrals, even without bad intent.