A more thorough explanation:
National Federation of Independent Business, et al. v. Sebelius, Secretary of Health and Human Services, et al. (2012) was a court case that decided if the
Patient Protection and Affordable Care Act of 2010 (ACA) was constitutional. The ACA required people to have health insurance or pay a penalty, and expanded Medicaid to more people. Some states and individuals sued the Secretary of Health and Human Services, arguing that the ACA was
unconstitutional. The
Supreme Court decided that the individual mandate was constitutional because it was a tax, but that the Medicaid expansion was unconstitutional because it was coercive. The Court said that the federal government cannot force states to follow federal
regulations. This case was important because it decided if the ACA was legal and affected many people's access to healthcare.