Enrolling in health insurance: Medicaid and the ACA marketplace

Seeing a doctor in the US without insurance is expensive. A single emergency room visit can run to tens of thousands of dollars. What many people do not realize is that a great many people who qualify for help never apply, either because they assume they will not qualify or because they are afraid of the effect on an immigration case.

The two main routes#

Medicaid: for lower incomes#

Medicaid is free or near-free coverage, funded jointly by the federal government and the states. Each state sets its own income limits, so whether you qualify genuinely depends on where you live.

Children usually qualify at much higher incomes than adults, through Medicaid or the CHIP program. Even when you do not qualify, your children may.

Medicaid takes applications all year round. There is no enrollment season to wait for.

The ACA marketplace: for everyone else#

If you have no coverage through an employer and your income is above the Medicaid limit, you buy a plan through the marketplace at HealthCare.gov. Some states run their own site, and HealthCare.gov redirects you to the right one.

The key point: most people who buy through the marketplace have part of their monthly premium paid by the government. The amount depends on your income and household size. Many people see the full sticker price, give up, and never find out they would only have paid a fraction of it.

At 65 the question changes shape, because the answer is Medicare rather than either route above. Elderly parents newly arrived in the US usually do not qualify straight away: Medicare for seniors who are new to the US covers the 5-year residence rule, what buying in costs, and what to use while waiting. If you already have Medicare and are weighing a change of plan, that is Medicare Open Enrollment: October 15 to December 7, a different season from the ACA marketplace, and confusing the two is common.

ACA open enrollment for 2027 coverage: key dates#

Enrollment for 2027 coverage opens on November 1 and closes on January 15. Outside that window most people cannot enroll at all. These are all five dates HealthCare.gov publishes (checked September 30, 2026):

• November 1: Open Enrollment starts. The first day you can enroll in, renew, or change plans for the coming year. Coverage can start as early as January 1.
• December 15: the last day to enroll or change plans if you want coverage to start on January 1.
• January 1: coverage starts for those who enrolled by December 15 and paid their first premium.
• January 15: Open Enrollment ends. The last day to enroll in or change a plan for the year.
• February 1: coverage starts for those who enrolled between December 16 and January 15 and paid their first premium.

The two dates people confuse are December 15 and January 15, and confusing them costs a month of coverage: December 15 is the deadline for coverage from the start of the year, January 15 is the final deadline. Enroll between them and coverage does not begin until February 1, so January is uncovered.

Coverage only actually starts once you have paid the first premium: both the January 1 and February 1 dates above carry that condition. The insurer sets the payment deadline, not the marketplace, so as soon as you have chosen a plan, ask the insurer when payment is due and pay before that date. Choosing a plan and not paying is how people arrive at a January appointment and find out they are uninsured.

Outside the window: Special Enrollment Periods and the 60-day clock#

From January 16 to October 31 you can only enroll if a life event gives you a Special Enrollment Period. HealthCare.gov groups these into six; all six are below, with the details that quietly cost people the right:

• Household changes in the past 60 days: getting married; having a baby, adopting, or placing a child in foster care; getting divorced or legally separated and losing coverage; someone on your plan dying, which causes you to lose the plan. The page states that divorce without losing coverage does not qualify you.
• Changes of residence: moving to a new home in a different ZIP code or county; moving to the US from a foreign country or a US territory; moving to or from the place you attend school, the place you both live and work as a seasonal worker, or a shelter or transitional housing. The page states that moving only for medical treatment, or staying somewhere on holiday, does not count.
• Loss of coverage: losing qualifying coverage in the past 60 days, or expecting to lose it in the next 60 days. Losing Medicaid or CHIP gives a wider window: 90 days.
• COBRA: when COBRA coverage expires or is no longer available, you have 60 days to enroll in a marketplace plan. The page states that voluntarily dropping COBRA does not qualify you, while losing it involuntarily does.
• An employer offer to help with the cost of coverage: being offered an individual coverage HRA (your employer may call it an "ICHRA") or a QSEHRA in the past 60 days, or expecting one in the next 60 days. The page says that in this case you have to ring the Marketplace Call Center to enroll, because you cannot do it online.
• More qualifying changes, and this group holds the item that matters most to recent immigrants: the page lists becoming a US citizen, gaining membership in a federally recognized tribe or ANCSA Corporation shareholder status, leaving incarceration, starting or ending service with AmeriCorps VISTA or the NCCC, and being affected by an unexpected and uncontrollable event or natural disaster. Naturalizing is a Special Enrollment Period: if you have just become a citizen, do not wait for November.

Two lines on that page are worth reading closely. In the individual-coverage block it says that if you do not provide acceptable documents about losing coverage, you will not qualify for the Special Enrollment Period. Its general notice is softer: you may have to submit documents confirming your loss of coverage. Either way the handling is the same: keep the letter from your old insurer and from your employer, from the day it arrives.

Can immigrants enroll#

This is the question that stops most people.

• Lawful permanent residents (green card holders), refugees, people granted asylum, and many other qualifying statuses can buy through the ACA marketplace and can receive premium help.
• Full Medicaid applies a waiting period to some statuses, but many groups are exempt from it, including refugees and people granted asylum. This particular point is changing, from October 1, 2026 (checked September 30, 2026): a CMS letter to the states (SHO 26-001) says that from that date, non-emergency Medicaid narrows to US citizens and nationals, lawful permanent residents with a green card, Cuban-Haitian entrants, and COFA migrants. A refugee who has not yet moved to a green card is no longer on that list. Medicare for seniors who are new to the US covers this in more detail. If this is your household, ask the state Medicaid office directly when you apply rather than relying on the sentence above.
• Children and pregnant women are covered more broadly in many states, sometimes where an adult in the same status would not be.
• People without lawful status cannot buy through the ACA marketplace, but emergency care is still available, and some states run their own programs for children or adults. Community health centers see everyone and charge on a sliding scale based on income.

What to have ready when you apply#

• Date of birth and Social Security number for each household member, where they have one
• Immigration documents for anyone applying for coverage
• An estimate of your household income for the year. On a wage, recent pay stubs make this easy; on a 1099, use the profit after expenses, the bottom line of Schedule C, not the total customers paid you
• Details of any coverage you already have through an employer

The application asks about the income of your whole tax household, not only yours.

Choosing a plan#

Marketplace plans come in tiers: Bronze, Silver, Gold, Platinum. Higher tiers cost more each month but leave you paying less when you actually receive care.

One thing that is easy to miss: if your income is low, Silver plans carry extra cost-sharing reductions that the other tiers do not. That often makes Silver the best value for a lower-income household, even though Bronze looks cheaper.

Before you commit, check two things: that the doctor you want is in the plan's network, and that any medication you take is on its covered list.

At tax time it gets reconciled, and one missing form costs the subsidy#

If you had marketplace coverage during the year you must file a tax return and reconcile the help paid towards your premiums, and if you used more credit than you qualified for you repay the difference. This is where self-employed people get caught, and it connects directly to taxes when the shop hands you a 1099.

The help paid towards your monthly premium is an advance tax credit, calculated on the income you estimate for the year ahead, not last year's income. HealthCare.gov says so explicitly. And for self-employed people it names which figure: enter "the income you expect to make from your business after expenses", that is the profit, not what customers paid you in total. At tax time the real figure is compared against the estimate, and HealthCare.gov's tax page states the following:

• If you had marketplace coverage during the year you must file a tax return and reconcile that credit, using Form 8962, based on the Form 1095-A the marketplace sends you.
• If you used more credit than you qualified for, you repay it, reporting the excess on that year's return.
• If you used less than you qualified for, you get a refund or a lower tax bill, but you still have to include Form 8962.
• An electronically filed return that is rejected for a missing Form 8962 has to be refiled, and the page says that when you refile you attach either Form 8962 or an explanation of why it is missing.
• From tax year 2026 onwards there is no cap on what you repay. The IRS questions-and-answers page on the premium tax credit (Q31, updated December 23, 2025) says that for tax years before 2026 a repayment cap could limit how much of the excess you had to repay, but that "there is no repayment cap for tax years after 2025. For tax years after 2025, you must repay the full amount by which your advance credit payments exceed your Premium Tax Credit." That change makes updating your income mid-year matter far more than it used to: there used to be a brake for lower incomes, and there is not one now. The IRS page also says that if the amount owed exceeds your refund, the IRS works with taxpayers on paying it off like any other tax balance.
• Not reconciling costs more than a delayed refund. The IRS page on the premium tax credit says you must file to reconcile even if you are not usually required to file, and that filing without reconciling "will delay your refund and may affect your eligibility for future advance credit payments." That is the bigger loss: a whole year of the subsidy.

HealthCare.gov's tax page says Form 1095-A arrives by mail by mid-February, and is usually in your account on the site from mid-January to February 1. Both dates belong to the tax season open when this was checked (checked September 30, 2026, when the page was written for 2025 taxes); that page is rewritten each January, so open it again for your own tax year.

The practical step takes a few minutes: when your income rises during the year, log in and update the figure then, rather than waiting until April of the following year. The IRS page says exactly that: telling the Marketplace about a change as soon as it happens lets it adjust the advance payment, which narrows the gap between the estimate and the real figure. Nail-salon income moves with the season; the amount to be repaid is calculated over the whole year.

Who helps for free, and who helps in Vietnamese#

None of these goes through an insurance salesperson, and none of them charges to file your application:

• The line with Vietnamese interpreters: 1-800-318-2596. HealthCare.gov's language page says, in Vietnamese, that you have the right to free help and information in your own language, and that to speak to a Vietnamese interpreter about the Health Insurance Marketplace you call that number.
• The right to an interpreter, not only while enrolling: your right to a free interpreter covers the clinic, the pharmacy and the emergency room, and how to complain if you are refused.
• Free local enrollment assisters: search by ZIP code at HealthCare.gov's find-local-help page.
• CMS's own Vietnamese-language material, including a family application form and an introduction to the marketplace, both in Vietnamese. The full list is on HealthCare.gov's language page.

If you have no coverage right now#

• Community health centers see uninsured patients and charge on a sliding scale. Find one at findahealthcenter.hrsa.gov
• Call 211 to ask about local assistance programs
• Many hospitals run a financial assistance program that reduces or cancels bills for lower-income patients. You have to ask; hospitals rarely offer it

What to do next#

• Go to HealthCare.gov and run the eligibility check; it takes a few minutes
• If your household income is low, apply for Medicaid today rather than waiting for an enrollment season
• Save the number of a nearby community health center in your phone, for when you need it quickly