Since the passage of the Affordable Care Act (ACA), there have been numerous actions in federal courts to challenge the constitutionality of the legislation. They include challenges by states against the ACA, reactions from legal experts with respect to its constitutionality, several federal court rulings on the ACA's constitutionality, the final ruling on the constitutionality of the legislation by the U.S. Supreme Court in National Federation of Independent Business v. Sebelius, and notable subsequent lawsuits challenging the ACA. The Supreme Court upheld ACA for a third time in a June 2021 decision.
