Health Insurance Marketplace: How Obamacare Works in the US

Moving to the United States requires planning in many areas, and healthcare is one of the most important. The Health Insurance Marketplace, commonly known as Obamacare, is the primary gateway for anyone who needs to purchase individual health insurance in the US. Understanding how this system works can mean the difference between a smooth transition and unwelcome financial surprises.

The Marketplace was created by the Affordable Care Act (ACA), signed into law in 2010, and brings together plans from private insurers on a centralized platform that allows comparison of prices, coverage, and subsidies. For immigrants who arrive in the country with valid legal status, the system offers accessible and standardized medical coverage options.

What the Marketplace Is

The Health Insurance Marketplace is an online platform managed by the federal government, accessible at HealthCare.gov, where US residents can search, compare, and purchase individual or family health plans. Some states operate their own marketplaces with slightly different rules and deadlines, such as California (Covered California) and New York (NY State of Health).

The ACA established minimum standards that all Marketplace plans must meet, including coverage of ten essential health benefit categories: outpatient care, emergency services, hospitalization, maternity care, mental health services, prescription drugs, rehabilitation, laboratory tests, preventive services, and pediatric care. No plan may deny coverage based on pre-existing conditions, which is a fundamental protection for those who arrive with a prior medical history.

Who Can Enroll

Eligibility to purchase a plan through the Marketplace covers US citizens, US nationals, and people lawfully present in the United States. This includes Green Card holders, holders of work visas such as H-1B, L-1, and O-1, students on F-1 visas, and other valid immigration statuses. Undocumented immigrants are not eligible for Marketplace plans.

In addition to immigration status, other requirements apply: the applicant may not be enrolled in Medicare and may not be currently incarcerated. People who have access to employer-sponsored health insurance that meets the ACA’s minimum coverage and affordability standards generally do not qualify for Marketplace subsidies, though they may choose to purchase an individual plan if they prefer.

Subsidies and Tax Credits

One of the main advantages of the Marketplace is the subsidies that reduce plan costs. The primary mechanism is the Advance Premium Tax Credit (APTC), which reduces the monthly premium based on household income. The lower the income relative to the federal poverty level, the larger the available subsidy.

It is important to note that the enhanced tax credits introduced during the pandemic by the American Rescue Plan Act and extended through the end of 2025 by the Inflation Reduction Act expired on December 31, 2025. In 2026, subsidies returned to original ACA levels, which means significantly higher premiums for many families. According to estimates by the Kaiser Family Foundation, average premium payments in the Marketplace increased approximately 114% compared to 2025. Congress has been discussing legislation to restore the enhanced credits, but as of April 2026 no final law had been passed by the Senate.

In addition to the APTC, there are Cost-Sharing Reductions (CSRs), available exclusively to those who choose Silver-category plans and have income between 100% and 250% of the federal poverty level. CSRs reduce deductibles, co-payments, and coinsurance, making the Silver plan effectively more generous at no additional cost.

Plan Types by Metal Level

Marketplace plans are organized into four metal categories, which indicate the average proportion of costs covered by the insurer:

• Bronze: covers approximately 60% of average costs. Lower premiums and higher deductibles, suited for healthy people who use few medical services.
• Silver: covers about 70% of costs. Offers a balance between premium and out-of-pocket expenses, and is the only level eligible for CSRs.
• Gold: covers approximately 80% of costs. Higher premiums but lower deductibles and co-payments, appropriate for those who use medical services frequently.
• Platinum: covers about 90% of costs. Highest premiums, but minimal out-of-pocket expenses.

Beyond the metal levels, there is the Catastrophic plan, available only to people under age 30 or those who qualify for a hardship exemption. This plan has very low premiums but only covers serious situations after a high deductible is met.

Provider Networks

Plans also vary according to the type of healthcare provider network:

• HMO (Health Maintenance Organization): requires selecting a primary care physician and obtaining referrals for specialists. Coverage is restricted to the plan’s network.
• PPO (Preferred Provider Organization): allows visits to specialists without a referral and offers partial out-of-network coverage at a higher cost.
• EPO (Exclusive Provider Organization): similar to an HMO, with no referral required, but no out-of-network coverage.
• POS (Point of Service): combines features of HMO and PPO, requiring referrals but allowing out-of-network care at an additional cost.

Enrollment and Deadlines

Purchasing plans through the Marketplace takes place during the Open Enrollment Period. For the 2026 plan year, the period ran from November 1, 2025 to January 15, 2026 in most states, with a December 15 deadline for coverage starting January 1. States with their own marketplaces may have different dates.

Outside of the open enrollment period, enrollment is only possible through a Qualifying Life Event, which opens a special 60-day window. Recognized events include:

• Moving to a different state or coverage area
• Marriage or divorce
• Birth or adoption of a child
• Loss of other health coverage, including loss of employer-sponsored insurance
• Change in immigration status
• Significant change in income

For newly arrived immigrants, obtaining legal status in the US constitutes a qualifying event, allowing enrollment outside the regular period. This is a crucial point for those planning a move: as soon as immigration status is established, coverage can be sought immediately, without waiting for the next open enrollment window.

Annual Spending Limits

All Marketplace plans have an out-of-pocket maximum, the annual ceiling on the insured’s own spending. In 2026, the maximum limit allowed by federal regulation is $10,600 for individual coverage and $21,200 for family coverage. Once this amount is reached in deductibles, co-payments, and coinsurance, the insurer covers 100% of eligible costs for the remainder of the year.

This mechanism serves as a financial safety net, especially important for those who are starting life in the United States and may not have substantial savings for medical emergencies. When choosing a plan, consider not only the monthly premium but the full range of potential costs over the year, including the deductible and out-of-pocket maximum. The HealthCare.gov website offers estimation tools that help compare plans available in your area.

Victoria Harper

Editor-in-Chief

Meet the author

Leading journalism and editorial content at Visto n’ Visa, Victoria helps make immigration topics clear, trustworthy, and easy to understand. Her focus is on delivering useful, human, and relevant content for people exploring new paths abroad.