In the United States, health insurance marketplaces, also called health exchanges, are organizations in each state through which people can purchase health insurance. People can purchase health insurance that complies with the Patient Protection and Affordable Care Act at ACA health exchanges, where they can choose from a range of government-regulated and standardized health care plans offered by the insurers participating in the exchange.

In the United States, health insurance helps pay for medical expenses through privately purchased insurance, social insurance, or a social welfare program funded by the government. Synonyms for this usage include "health coverage", "health care coverage", and "health benefits". In a more technical sense, the term "health insurance" is used to describe any form of insurance providing protection against the costs of medical services. This usage includes both private insurance programs and social insurance programs such as Medicare, which pools resources and spreads the financial risk associated with major medical expenses across the entire population to protect everyone, as well as social welfare programs like Medicaid and the Children's Health Insurance Program, which both provide assistance to people who cannot afford health coverage.