Healthcare Policy & Insurance Editor · Last reviewed January 2025
The Affordable Care Act established Health Insurance Marketplaces — also called exchanges — where individuals and families who don't have access to employer-sponsored insurance or government programs can purchase regulated health insurance. The federal marketplace at healthcare.gov serves most states; some states operate their own marketplaces.
The Metal Tier System
Marketplace plans are categorized into four metal tiers that describe the average share of covered costs the plan pays for a typical enrollee. Actuarial values are approximate:
- Bronze — Plan pays ~60% of covered costs; lowest premiums but highest cost-sharing when care is needed. Appropriate for healthy individuals who primarily want catastrophic protection.
- Silver — Plan pays ~70% of covered costs. The critical tier for subsidy-eligible enrollees — cost-sharing reductions (CSRs) are only available on silver plans. For low-to-moderate income enrollees who qualify for CSRs, silver plans can be extremely cost-effective.
- Gold — Plan pays ~80% of covered costs; higher premiums, lower cost-sharing. Appropriate for those who anticipate significant healthcare use.
- Platinum — Plan pays ~90% of covered costs; highest premiums. Appropriate for those with very high healthcare needs.
Premium Tax Credits (Subsidies)
Premium tax credits are available to individuals and families with incomes between 100% and 400% of the federal poverty level (and, under the Inflation Reduction Act through 2025, extended to higher incomes with a cap on premiums as a percentage of income). The credit is calculated to reduce the cost of a benchmark silver plan to a defined percentage of income. Credits can be taken monthly (advance premium tax credits) to reduce premiums, or claimed on the annual tax return.
Cost-Sharing Reductions (CSRs)
Cost-sharing reductions reduce the deductibles, copays, and coinsurance on silver plans for enrollees with incomes below 250% FPL. At the highest CSR tier (100–150% FPL), silver plans effectively function like platinum plans. Enrollees who qualify should almost always choose a silver plan to access CSRs — even if the premium appears higher than a bronze plan, the dramatically reduced cost-sharing typically more than compensates.
Open Enrollment and Special Enrollment Periods
Open enrollment for marketplace plans runs from November 1 through January 15 in most states (dates vary for state-based exchanges). Outside open enrollment, coverage can only be obtained through a Special Enrollment Period triggered by a qualifying life event — loss of other coverage, marriage, birth/adoption, or change in income or household size.
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