ACA Marketplace

Key facts

Created by

Patient Protection and Affordable Care Act (2010)

First coverage year

2014

Regulations

45 CFR Parts 155 and 156

Platforms

HealthCare.gov (federal) or a state-based marketplace

Plan metal levels

Bronze, Silver, Gold and Platinum, plus catastrophic plans

What is the ACA Marketplace?

The Affordable Care Act (ACA) required a marketplace, also called an exchange, in every state. Some states run their own state-based marketplace, while others rely on the federally facilitated marketplace operated by CMS through HealthCare.gov. Private insurers sell qualified health plans (QHPs) on these marketplaces after certification.

The Marketplace mainly serves people without access to affordable employer coverage, Medicare or Medicaid. About 24 million people selected a Marketplace plan during open enrollment for 2025 coverage, a record at the time. Totals for later years depend on changes to premium subsidies, so check the latest CMS enrollment report.

How Marketplace coverage works

Marketplace plans follow a common structure:

• Metal levels reflect actuarial value, the average share of covered costs the plan pays: about 60% for Bronze, 70% for Silver, 80% for Gold and 90% for Platinum.
• Premium tax credits lower monthly premiums based on household income and the cost of the second-lowest-cost Silver plan in the area.
• Cost-sharing reductions lower deductibles and copays for lower-income enrollees who choose a Silver plan.
• Enrollment is limited to an annual open enrollment period and special enrollment periods triggered by events such as losing other coverage.
• Plans must cover essential health benefits, including prescription drugs, and cannot deny coverage or charge more because of pre-existing conditions.

Recent changes to Marketplace rules

Enhanced premium tax credits, enacted in 2021 and extended in 2022, removed the upper income limit on eligibility and increased subsidies through the 2025 plan year. Their continuation, along with federal changes to enrollment periods and eligibility verification, has been contested in Congress and the courts, so rules and figures for 2026 onward should be checked against current CMS guidance.

Why the Marketplace matters

Marketplace plans often use narrower provider networks than employer plans to keep premiums low, so network inclusion affects patient access and provider volume in regions with many individual-market enrollees. CMS publishes Marketplace public use files with plan attributes, rates, service areas and benefits, which analysts use to compare insurers, premiums and cost sharing county by county. For drug makers, Marketplace formularies must meet essential health benefits rules on minimum drug counts per category, which makes them a distinct formulary segment.