The United States covers people through a patchwork of employer plans, individual marketplaces, Medicare, Medicaid, and military and veterans systems. Millions remain uninsured or underinsured, and costs per person are the highest among wealthy nations.
Employer-sponsored coverage is the largest single source, a legacy of wartime wage controls reinforced by the tax exclusion for employer premiums. It ties insurance to employment in a way most peer countries do not.
The Affordable Care Act expanded coverage through subsidized marketplaces, Medicaid expansion at state option, and rules barring denial for pre-existing conditions. Coverage rose substantially while cost growth continued.
Comparisons with other wealthy nations show the US spending far more per person without corresponding gains on common health measures. Analysts attribute the gap variously to administrative complexity, prices paid for services and drugs, utilization patterns, and underlying population health.