Open enrollment for health insurance typically runs from November 1 to January 15 for the federal marketplace, though some states like California push that deadline to January 31. Medicare follows its own drumbeat from October 15 to December 7, because why make things simple? Federal employees get stuck with November 10 to December 8. Missing these windows means no coverage unless life throws a curveball like marriage or job loss. There’s more to know about making these deadlines work.
Design Highlights
- Federal Marketplace open enrollment runs from November 1 to January 15 annually for most states.
- Medicare open enrollment occurs earlier, from October 15 to December 7 each year.
- Some states like California extend enrollment through January 31, while Idaho ends December 15.
- Selecting a plan by December 15 ensures coverage starts January 1; later selections begin February 1.
- Special enrollment periods allow enrollment outside regular periods for qualifying life events like job loss or marriage.
When Is Open Enrollment for Health Insurance
Open enrollment for health insurance—when is it, exactly? For most Americans using the federal Health Insurance Marketplace, it runs from November 1 to January 15 every year. Simple enough. But nothing about health insurance stays simple for long.
Mark your calendar: federal Marketplace open enrollment runs November 1 through January 15, but timing your selection determines when coverage actually begins.
Here’s where timing matters. Select a plan by December 15, and coverage kicks in January 1. Wait until December 16 through January 15? Coverage starts February 1. Miss the deadline entirely and there’s no coverage unless a qualifying life event happens. And here’s a fun twist—automatic re-enrollment occurs after December 15 for anyone who doesn’t actively choose a new plan. Whether that’s good or bad depends entirely on whether the old plan still works.
Medicare follows its own calendar because of course it does. Medicare Open Enrollment runs October 15 to December 7, covering Medicare Advantage and Part D prescription drug plans. Changes become effective January 1.
Federal employees get yet another window: November 10 to December 8 for the Federal Employee Health Benefits Open Season, which includes dental, vision, and flexible spending accounts. The enrollment system slams shut at 11:59 pm local time on December 8. No exceptions.
State-based Marketplaces throw their own curveballs into the mix. California runs enrollment through January 31. So do New Jersey, New York, Rhode Island, and Washington DC. Massachusetts extends to January 23. Idaho, however, ends December 15.
Georgia moved to its own Marketplace for 2025, separate from HealthCare.gov entirely. Each state provides localized enrollment assistance, which sounds helpful until managing which deadlines apply where.
Then there are Special Enrollment Periods. These exist for people who experience qualifying life events like losing coverage or getting married. SEPs allow enrollment outside regular Open Enrollment, and coverage can start anytime within the qualifying window.
People auto-re-enrolled to a different insurer get until December 31 to pick a new plan for January coverage.
What should someone actually consider during Open Enrollment? Healthcare needs, preferred doctors, medications. Financial capability around premiums, deductibles, out-of-pocket costs. Plan costs change. Covered services change. Provider networks change. Reviewing these annually isn’t optional, really. Four in five customers can find coverage for $10 or less per month thanks to expanded financial assistance that continues through 2025. Health care tax credits can potentially lower monthly costs for those who qualify. Just as health insurance premiums vary by coverage needs and location, homeowners insurance costs have also seen significant increases, with national averages rising 24% from 2021 to 2024 due to inflation and severe weather.
Marketplace and insurer websites offer comparison tools, though quality varies.
The takeaway? Open Enrollment timing depends on which program applies. Federal Marketplace, Medicare, federal employee benefits, state-based Marketplaces—all operate on different schedules. Missing deadlines means waiting or scrambling for Special Enrollment Period eligibility.
December 15 remains the critical date for maximizing coverage start options in most scenarios.
Frequently Asked Questions
What Happens if I Miss the Open Enrollment Deadline?
Missing the open enrollment deadline means no health insurance changes until next year—unless someone qualifies for a Special Enrollment Period through life events like marriage, birth, or job loss.
Current Marketplace members get auto-re-enrolled into their existing plan, but they can’t switch anything.
No coverage? That means paying full price for medical bills and potentially facing state penalties.
The earliest new coverage starts is February 1 if enrolled between December 16 and January 15. Otherwise, people wait.
Can I Change My Health Insurance Plan Outside of Open Enrollment?
Yes, but only with a qualifying life event.
Lost coverage? Moved? Got married or had a baby? Those trigger a Special Enrollment Period—usually 60 days to make changes. Job-based plans must offer at least 30 days.
But here’s the catch: proof is required. Marriage certificate, birth certificate, loss of coverage notice—whatever validates the event. Moving for vacation doesn’t count, obviously.
Medicaid and CHIP? Those are available year-round, no special event needed.
How Do I Enroll in Health Insurance During Open Enrollment?
Starting November 1, people head to HealthCare.gov or their state marketplace and create an account. They fill out an application with household size, income, and current insurance status.
Then they compare plans—premiums, deductibles, networks, the works. Online tools help, or they can call marketplace agents.
Pick a plan by December 15 for January 1 coverage, or by January 15 for February 1 start. Pay that first premium or coverage won’t activate.
Does Open Enrollment Apply to Employer-Sponsored Health Insurance Plans?
Yes, open enrollment absolutely applies to employer-sponsored health insurance plans.
It’s the annual window—usually 2-4 weeks in fall—when employees can enroll, switch plans, or drop coverage without needing a qualifying life event.
Each employer sets their own dates, typically between October and December before a January 1 start.
Miss it? Too bad. Employees are stuck with their current plan until next year unless something major happens like getting married or having a baby.
What Documents Do I Need to Enroll in Health Insurance?
Applicants need identification documents like a U.S. passport or birth certificate. Social Security card or tax forms work too.
Proof of income is required—recent pay stubs, tax returns for the self-employed, or documentation for unemployment benefits and other income sources.
Residency proof matters, think utility bills or lease agreements. Household member information gets collected. Special circumstances? Marriage certificates, adoption papers, whatever applies.
Documents get submitted through online portals, usually within 90-95 days. Miss the deadline, risk losing coverage. Pretty straightforward stuff.
