Obtaining citizenship or lawful permanent resident status will trigger a special enrollment period

Becoming a U.S. citizen, U.S. national, or lawfully present individual is a qualifying life event that triggers a 60-day special enrollment period in the exchange/Marketplace.¹

Coverage is effective the first of the month following the enrollment.²

Unlike most other qualifying life events,³ this one only applies if you’re enrolling through the exchange (either the federally run HealthCare.gov or a state-run exchange). Off-exchange, carriers can allow this special enrollment period or not – it’s at their discretion.

Read more about how immigrants can obtain health coverage in the United States.

Becoming a U.S. citizen is a qualifying life event

Becoming a U.S. citizen involves completing the naturalization process.⁴ Once you gain citizenship, you have 60 days to enroll in a health insurance plan through the exchange, and your coverage will be effective the first of the month after you apply.¹

Note that a special enrollment period does not apply if you already had a lawfully present immigration status prior to becoming a citizen. Any change in immigration status only triggers a special enrollment period if the person did not previously have a lawfully present immigration status. Switching from one lawfully present status to another does not trigger a special enrollment period.⁵

If you’re a U.S. national living in a U.S. state, you may be eligible for a SEP

All U.S. citizens are U.S. nationals, but the reverse is not necessarily true.⁶ People born in American Samoa – including Swains Island – are U.S. nationals, but are not U.S. citizens unless they move to a U.S. state for at least three months and then go through the naturalization process.⁷

People born in the Northern Mariana Islands are granted U.S. citizenship, but can elect instead to be non-citizen U.S. nationals. People born in the other U.S. territories – Guam, Puerto Rico, and the U.S. Virgin Islands – are U.S. citizens.⁶

Most of the ACA’s provisions do not apply in the U.S. territories.⁸ (This is a reversal of the position that the Department of Health and Human Services (HHS) took in 2013, when they said that the ACA would apply in the territories.) Still, plans sold in the territories cannot have annual or lifetime benefit maximums, and must cover preventive care with no cost-sharing.⁹

None of the territories has established an exchange, and HealthCare.gov does not offer plans in the territories.⁹ The annual open enrollment period does not apply in the territories, since the ACA’s requirement that health plans be guaranteed-issue is not applicable in the territories.

So it’s important to note that someone who becomes a U.S. national is eligible for a special enrollment period (SEP), but they have to move to a U.S. state in order to take advantage of it, since that’s where ACA-compliant plans are offered.

Medicare and Medicaid are available to eligible residents in U.S. territories, and the Centers for Medicare & Medicaid Services (CMS) website has resource pages for people in the territories, with contact information for the available programs.

Your SEP starts when you become a U.S. citizen, national, or lawfully present individual

There is a wide range of immigration statuses that qualify as “lawfully present.”¹⁰ Lawfully present U.S. residents can enroll in health plans through the exchange (HealthCare.gov or a state-run platform, depending on where they live), and have a special enrollment period that runs for 60 days from the date that they gain lawfully present resident status in the U.S.

Note: DACA – Deferred Action for Childhood Arrivals – recipients cannot use the health insurance Marketplace to obtain coverage. DACA recipients briefly had access to the Marketplaces in late 2024 and 2025, but this ended in August 2025 due to a federal rule change.

Washington state obtained federal permission to allow undocumented immigrants to use its Marketplace as of 2024, and Colorado has created a separate platform where people can enroll in coverage if they aren’t eligible to use the Marketplace due to immigration status. (In both Washington and Colorado, state-funded subsidies are available for these enrollees.)¹¹

New immigrants with income below the federal poverty level are no longer eligible for premium subsidies

The SEP triggered by gaining citizenship or lawfully present resident status applies regardless of income, and regardless of whether the person is eligible for premium subsidies in the Marketplace. Eligibility for premium subsidies for new immigrants (those who have been in the U.S. less than five years) used to differ from the rules for other Marketplace enrollees, but that is no longer the case.

As of 2026, recent immigrants with income below the federal poverty level are no longer eligible for Marketplace subsidies during the five-year window before they become eligible for Medicaid. Prior to 2026, these immigrants could qualify for Marketplace subsidies with income as low as $0, but the "Big Beautiful Bill," enacted in 2025, ended that provision.

Although the ACA generally has a subsidy eligibility floor equal to 100% of the federal poverty level (FPL), ACA Section 36B(c)(1)(B) provided subsidy eligibility for lawfully present residents with income below 100% of FPL if they were not eligible for Medicaid as a result of their immigration status.¹² (Lawfully present residents generally have a five-year waiting period before they can be eligible for Medicaid, although some states use state funds to provide Medicaid coverage to lawfully present residents who have not met the five-year waiting period requirement). But that ended in 2026, due to the federal legislation that was enacted in 2025.

Immigrants age 65 and older are eligible for a SEP when they become lawfully present individuals

Prior to 2014, individual market plans generally did not accept applicants who were 65 and older, even if they were ineligible for Medicare. (There were some exceptions, and some states had high-risk pools that would cover these applicants. The Texas high-risk pool was one example.)¹³ Immigrants are not allowed to purchase Medicare until they’ve been in the U.S. for five years.¹⁴

Before the ACA took effect, these older immigrants were in a tough spot for health insurance, since they also weren’t able to purchase individual market coverage. The ACA changed that. People 65 and older who aren’t eligible for Medicare are allowed to purchase individual market coverage, with premium subsidies and cost-sharing reductions available if their income makes them eligible. And their unsubsidized premiums cannot be more than three times the premiums charged for a 21-year old.¹⁵ So a person who becomes a lawfully present U.S. resident has access to the special enrollment period even if he or she is 65 or older.

And premium subsidies are available (depending on the person’s income) in the exchange/Marketplace as long as the person is not eligible for premium-free Medicare Part A.¹⁶ This will generally be the case for older immigrants, since they typically don’t have the ten years of work history in the U.S. necessary to qualify for premium-free Medicare Part A. These individuals can continue to receive premium subsidies indefinitely (again, depending on income), since they would have to pay a premium for Medicare Part A once they’ve been in the U.S. for five years and can enroll in Medicare. But note that if they ever did want to transition to Medicare, a late enrollment penalty would apply if they continued to use the exchange/marketplace coverage after the five-year waiting period for Medicare eligibility.¹⁷

Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written hundreds of opinions and educational pieces about the Affordable Care Act for healthinsurance.org.