The Affordable Care Act (ACA) is a 2010 law that made several changes to the US health insurance system, including expanding Medicaid in some states, allowing young adults to stay on their parents’ plans until age 26, prohibiting coverage denials for preexisting conditions, and creating new health insurance marketplaces.

The ACA Marketplace is one part of that law. It is the platform where individuals and families can shop for and enroll in private health insurance plans that meet ACA standards, often with income-based subsidies that lower costs. The Marketplace is a purchasing platform, not a single insurance program.