What the ACA changed
The Patient Protection and Affordable Care Act (ACA) reshaped individual and small-group health insurance in the United States. Its best-known consumer protection concerns pre-existing conditions. According to HealthCare.gov, no insurance plan can reject you, charge you more, or refuse to pay for essential health benefits because of a condition you had before coverage started. Once you are enrolled, the plan cannot drop you or raise your rate based only on your health. Medicaid and CHIP follow the same rule.
The main exception is a grandfathered individual policy bought on or before March 23, 2010. Such plans do not have to cover pre-existing conditions. Holders can switch to a Marketplace plan during Open Enrollment or when their plan year ends.
The ten essential health benefits
Marketplace plans must cover ten categories of essential health benefits, as listed on HealthCare.gov:
- Ambulatory (outpatient) patient services
- Emergency services
- Hospitalization
- Pregnancy, maternity and newborn care
- Mental health and substance use disorder services, including behavioral health treatment
- Prescription drugs
- Rehabilitative and habilitative services and devices
- Laboratory services
- Preventive and wellness services and chronic disease management
- Pediatric services, including oral and vision care
Adult dental and vision coverage are not essential health benefits. If you need them, look for separate dental or vision plans.
Marketplace and open enrollment
Individuals and families without job-based coverage can buy plans through the Health Insurance Marketplace at HealthCare.gov or through their state's own exchange. For 2027 coverage, HealthCare.gov lists these key dates:
| Date | What happens |
|---|---|
| November 1 | Open Enrollment starts for 2027 coverage |
| December 15 | Last day to enroll or change plans for coverage that starts January 1 |
| January 15 | Open Enrollment ends |
States that run their own exchanges may set different deadlines, so check your state's site. Outside Open Enrollment you need a Special Enrollment Period. Qualifying events include marriage, a birth or adoption, a move to a new ZIP code or county, losing job-based coverage or Medicaid, and aging off a parent's plan at 26. When COBRA coverage ends, HealthCare.gov says you have 60 days to enroll in a Marketplace plan.
Premium tax credits after 2025
The premium tax credit lowers your monthly Marketplace premium. HealthCare.gov describes the eligible range as household income between 100% and 400% of the federal poverty level. Cost-sharing reductions can also lower deductibles and copays for eligible enrollees in silver plans.
The temporary "enhanced" credits that had expanded eligibility were not renewed. KFF reported in 2026 that the enhanced premium tax credits expired, and that the average Marketplace deductible rose from $2,759 in 2025 to $3,786 in 2026, the steepest increase it had recorded. KFF also reported that Marketplace enrollment fell in 2026 for the first time in seven years. Before you choose a plan, use the official estimator at HealthCare.gov. Final 2027 income levels are posted when Open Enrollment begins.
The employer mandate
The ACA does not force every employer to offer coverage, but it puts a price on not doing so for large employers. According to the IRS, an applicable large employer (ALE) is one that had an average of at least 50 full-time employees, including full-time-equivalent employees, in the prior calendar year. An ALE may owe an employer shared responsibility payment in two cases:
- It does not offer coverage to at least 95% of full-time employees, and at least one full-time employee receives a premium tax credit in the Marketplace.
- It offers coverage, but the coverage is unaffordable or does not provide minimum value for an employee who then receives a premium tax credit.
The amounts are indexed every year. The IRS table showed $2,970 and $4,460 per employee for the two payment types in 2024. Smaller employers have no federal penalty, but many offer group plans to compete for workers. See our employee benefits section.
Is there still an individual mandate?
At the federal level, no. HealthCare.gov states that the fee for not having health insurance no longer applies and was charged only for plan years 2018 and earlier. Some states have their own rules. California, for example, adopted a state individual health care mandate with a penalty assessed on the state tax return. Check your state before going without coverage.
How to use this information
- Compare the full cost of a plan: premium, deductible, out-of-pocket maximum and provider network.
- Report income changes to the Marketplace during the year to avoid repaying credits at tax time.
- Keep proof of any life event that may qualify you for a Special Enrollment Period.
- Read more in our health insurance guide. Policies are issued by licensed insurers and placed through licensed producers in your state. You can also request a quote.