Marketplace open enrollment lasts 76 days each year, running from November 1 through January 15 on HealthCare.gov. For 2026 coverage, the window opens November 1, 2025, and closes January 15, 2026.1Centers for Medicare & Medicaid Services. Marketplace 2026 Open Enrollment Fact Sheet After January 15, you can only enroll in or switch plans if a qualifying life event opens a special enrollment period.2HealthCare.gov. Get Answers
The December 15 Deadline Inside the Window
The 76-day window has two halves, and the split matters. Pick a plan by midnight on December 15 and pay your first premium, and coverage begins January 1.3HealthCare.gov. When Can You Get Health Insurance Enroll between December 16 and January 15, and coverage does not start until February 1, leaving you uninsured for the month of January.1Centers for Medicare & Medicaid Services. Marketplace 2026 Open Enrollment Fact Sheet
So the practical deadline for full-year coverage is December 15, not January 15. The extra month exists for people who need more time, but it costs you the start of the year.
Coverage Doesn’t Begin Until You Pay
Selecting a plan is not the same as being covered. Your insurance company has to receive your first monthly premium before coverage activates. Some insurers require payment before the coverage start date; others accept it shortly after.4Centers for Medicare & Medicaid Services. I Signed Up for a Marketplace Plan, But I’m Not Sure I Have Coverage Contact the insurer directly after you enroll to confirm the payment amount, method, and due date. Miss that payment and the enrollment can be canceled even though you finished the application on time.
If You Already Have a Plan and Do Nothing
Current marketplace members who take no action during open enrollment are automatically re-enrolled for the following year, so coverage does not lapse.5HealthCare.gov. Automatic Re-Enrollment Keeps You Covered Convenient, but not always cheap. Premiums, provider networks, and your subsidy amount can all shift from one year to the next, so the plan you land in may cost more than a comparable option you would have chosen deliberately.
Two things follow from that. If you want to drop marketplace coverage entirely for the new plan year, act before December 15 or the system will re-enroll you. And even after auto-enrollment happens, you can still switch to a different plan any time before January 15 closes the window.
Missing the Window: Special Enrollment Periods
Outside the annual window, the only way in is a special enrollment period triggered by a qualifying life event. You generally have 60 days from the date of the event to pick a plan.6HealthCare.gov. Special Enrollment Period (SEP) – Glossary
Events that open a 60-day window include:
- Losing existing health coverage, such as employer-sponsored insurance, a spouse’s plan, or aging off a parent’s plan.7HealthCare.gov. Getting Health Coverage Outside Open Enrollment
- Getting married.
- Having a baby, adopting, or taking in a foster child. Coverage for the child can be backdated to the date of the event even if you enroll up to 60 days later.8HealthCare.gov. Coverage for Pre-Existing Conditions
- Moving to a new ZIP code or county, provided you had qualifying coverage for at least one day in the 60 days before the move.7HealthCare.gov. Getting Health Coverage Outside Open Enrollment
- Gaining a dependent through a court order, being affected by a FEMA-declared disaster, or being harmed by an enrollment error on HealthCare.gov.9HealthCare.gov. Special Enrollment Periods for Complex Health Care Issues
Losing Medicaid or CHIP is the one common event with a longer window: 90 days rather than 60.10HealthCare.gov. Send Documents to Confirm a Special Enrollment Period
When Special Enrollment Coverage Starts
During a special enrollment period, the day you finish picking a plan drives your start date. Finalize by the 15th of a month and coverage generally begins on the first of the next month. Finalize after the 15th and it starts the first of the month after that. Enrolling on June 10 gets you a July 1 start; enrolling on June 20 pushes you to August 1.3HealthCare.gov. When Can You Get Health Insurance Birth, adoption, and foster placement are the exception: coverage can be backdated to the event.8HealthCare.gov. Coverage for Pre-Existing Conditions
The Low-Income Year-Round Sign-Up Is Gone
In recent years, people with household incomes at or below 150 percent of the federal poverty level could enroll in marketplace coverage at any time. That option no longer exists for the 2026 plan year. CMS repealed the low-income special enrollment period, citing concerns about unauthorized enrollments and adverse selection.11Centers for Medicare & Medicaid Services. 2025 Marketplace Integrity and Affordability Final Rule Medicaid remains a year-round program, so if your income is low enough to qualify for it, you can still apply anytime.
State Exchanges Sometimes Run Longer
The November 1 to January 15 window is the federal HealthCare.gov schedule. More than a dozen states and the District of Columbia run their own exchanges, and several set deadlines that extend past January 15, into late January or February. Illinois joined that group for 2026, moving off HealthCare.gov to its own state-run marketplace.1Centers for Medicare & Medicaid Services. Marketplace 2026 Open Enrollment Fact Sheet
If your state runs its own exchange, check that exchange’s website for its exact dates. Missing a state deadline has the same effect as missing the federal one: you need a qualifying life event to enroll before the next open enrollment.
If You Miss Every Deadline
Without open enrollment and without a qualifying event, marketplace coverage is off the table until the next November 1. A few alternatives exist, though none replace a full marketplace plan.
Medicaid and CHIP have no enrollment window. Applications are accepted year-round, and if you qualify based on income and household size, coverage can start right away.12InsureKidsNow.gov. Frequently Asked Questions You can apply through HealthCare.gov or directly with your state’s Medicaid agency.
Short-term, limited-duration insurance can bridge the gap to the next open enrollment. Under federal rules that took effect in September 2024, new short-term plans can last no more than three months, with a total maximum of four months counting any renewals or extensions.13Federal Register. Short-Term, Limited-Duration Insurance and Independent, Noncoordinated Excepted Benefits Coverage These plans are not required to cover pre-existing conditions, may exclude prescription drugs or mental health care, and do not qualify for marketplace subsidies. They are a stopgap, not a replacement.
A handful of states and the District of Columbia also impose a tax penalty on residents who go without qualifying coverage, so in those places going uninsured after a missed deadline carries a direct financial cost in addition to the medical risk.