The ACA Marketplace is where people without employer coverage, Medicare or Medicaid buy individual and family health insurance. Most people can only sign up or switch plans during open enrollment, so it pays to know the dates, and the one deadline that decides when your coverage starts.
Open enrollment dates for 2027 coverage
| If you enroll (HealthCare.gov states) | Coverage starts |
|---|---|
| November 1 – December 15, 2026 | January 1, 2027 |
| December 16, 2026 – January 15, 2027 | February 1, 2027 |
These are the dates on HealthCare.gov's dates and deadlines page. If your state runs its own exchange, it sets its own dates, so check your state's site.
You may have read that open enrollment would end on December 15 this year. A 2025 federal rule made that change, but after court rulings HealthCare.gov lists January 15, 2027 as the last day. Rules like this can change, so confirm the dates on HealthCare.gov before you plan around them.
Either way, aim for December 15: it's the deadline for coverage starting January 1, and it gives you time to estimate next year's income, check that your doctors and prescriptions are covered, and compare plans.
What the metal tiers mean
Plans are grouped into tiers by how costs are split between you and the plan. On average, a Bronze plan pays about 60% of covered costs, Silver about 70%, Gold about 80% and Platinum about 90%, according to HealthCare.gov's guide to the metal categories. The tier tells you nothing about the quality of care or the doctors in the network, so check the network separately: see HMO vs. PPO vs. EPO.
| Tier | Premium | Cost when you get care | Often suits |
|---|---|---|---|
| Bronze | Lowest | Highest | People who rarely use care and want protection from big bills |
| Silver | Moderate | Moderate (lower with cost-sharing reductions) | People who qualify for extra savings |
| Gold | Higher | Lower | People who expect regular care |
| Platinum | Highest | Lowest | People with high, predictable medical use (not offered everywhere) |
How subsidies lower your cost
Premium tax credits
A premium tax credit reduces your monthly premium based on your estimated household income and size for the coverage year. You can have it paid directly to your insurer each month. If your income turns out different from your estimate, the difference is settled on your tax return (the IRS explains how the credit is reconciled), so update the Marketplace when your income changes.
Cost-sharing reductions
If your income is low enough, Silver plans come with cost-sharing reductions that lower your deductible, copays and out-of-pocket maximum. You must pick a Silver plan to get them (HealthCare.gov: saving on out-of-pocket costs).
Don't just auto-renew
If you're already enrolled and don't act by December 15, you may be automatically re-enrolled for January 1, in the same plan or a similar one from your insurer. But premiums, networks and drug lists change every year, and your savings depend on this year's income estimate. Log in during open enrollment, update your income, and compare at least a few plans.
A checklist before you pick a plan
- Estimate your household income for 2027.
- List your doctors, hospitals and prescriptions, and check each plan's network and formulary.
- Compare each plan's premium plus its deductible and out-of-pocket maximum.
- Choose by December 15 for coverage that starts January 1 (or by January 15 for February 1) if you're in a HealthCare.gov state.
Outside open enrollment
You can still enroll after a qualifying life event, such as losing job-based coverage, moving, marriage or a new baby. If you're leaving a job, compare your options in COBRA vs. a Marketplace plan.
New to the vocabulary? Start with how health insurance works.
