When Is Open Enrollment for Health Insurance 2025? Key Dates

Missing the health insurance enrollment window can mean a full year without coverage — or paying a lot more than you expected. Whether you’re shopping on the ACA Marketplace, navigating Medicare, or using a state exchange like Covered California, the 2025-2026 open enrollment dates matter more than ever, and this guide lays out every key deadline, state-level exception, and what happens if life gets in the way.

ACA Open Enrollment Start Date: November 1, 2025 ·
ACA Open Enrollment End Date: January 15, 2026 ·
Coverage Start Date (ACA): January 1, 2026 ·
Medicare AEP Start Date: October 15, 2025 ·
Medicare AEP End Date: December 7, 2025 ·
Open Enrollment Frequency: Once per year

To make the most of open enrollment, follow these steps:

1. Mark key deadlines on your calendar: Medicare AEP starts October 15; ACA enrollment opens November 1.
2. Determine if you qualify for premium tax credits using the Marketplace subsidy calculator.
3. Compare plans from different insurers based on metal tier, network, and out-of-pocket costs.
4. Enroll before the deadline and pay your first premium to start coverage.

Six key facts, one pattern: the 2025-2026 open enrollment cycle is split into distinct windows for ACA Marketplace and Medicare, with state-level variations that can trap the unwary.

When Is Open Enrollment for Health Insurance 2025?

ACA Open Enrollment Dates for 2025

• For most states using HealthCare.gov, open enrollment for 2025-2026 coverage begins November 1, 2025 and ends January 15, 2026 (KFF (nonpartisan health policy research)).
• Consumers who select a plan by December 15, 2025 can get coverage starting January 1, 2026 (HealthCare.gov (government marketplace)).
• If you enroll between December 16 and January 15, 2026, coverage begins February 1, 2026 after the first premium is paid (HealthCare.gov (government marketplace)).

State-Specific Deadlines

• States like California, Connecticut, District of Columbia, Illinois, New Jersey, New York, Pennsylvania, and Rhode Island close on January 31, 2026 — 16 days later than the federal deadline (KFF (nonpartisan health policy research)).
• Idaho began its reporting period earlier, on October 15, 2024 for the 2025 coverage year (CMS (federal marketplace data)).
• New York began processing plan selections on November 16, 2024 for 2025 coverage (CMS (federal marketplace data)).
• Rhode Island extended its 2025 open enrollment to February 28, 2025 due to a cybersecurity breach affecting the RIBridges system (CMS (federal marketplace data)).

What If You Miss Open Enrollment?

• Outside open enrollment, you can only enroll if you qualify for a Special Enrollment Period (SEP) due to a qualifying life event — losing other coverage, marriage, birth, adoption, or moving (HealthCare.gov (government marketplace)).
• A Special Enrollment Period generally lasts 60 days from the qualifying event.
• If you miss both open enrollment and any SEP, you typically go without Marketplace coverage until the next annual window — a gap that can mean a full year uninsured.

The pattern: Missing open enrollment has consequences, but knowing the dates and your state’s rules can keep you covered.

What Is Open Enrollment?

Definition of Open Enrollment

• Open enrollment is the annual period when individuals can sign up for health insurance or make changes to their existing coverage (Medicare.gov (federal program guidance)).
• It applies to ACA Marketplace plans, state-based exchanges, and Medicare Advantage / Part D plans separately.
• Outside this window, you can only enroll with a qualifying life event that triggers a Special Enrollment Period.

Who Can Enroll During Open Enrollment?

• Open enrollment is open to any individual lawfully present in the U.S., including those who are uninsured or switching plans.
• There is no medical underwriting — insurers cannot deny coverage or charge higher premiums due to pre-existing conditions.
• Income-based premium tax credits are available through the Marketplace for those earning between 100% and 400% of the federal poverty level.

What Plans Are Available?

• Marketplace plans come in four metal tiers: Bronze, Silver, Gold, and Platinum — each covering a different percentage of average costs.
• Catastrophic plans are available for people under 30 or those with a hardship exemption.
• Medicare beneficiaries choose between Original Medicare (Parts A and B) with or without Part D, or Medicare Advantage (Part C) which bundles hospital, medical, and often drug coverage.

The pattern: open enrollment is the insurance industry’s annual “reset button” — everyone gets a fair shot regardless of health history. Miss it, and the security net tightens considerably.

How Often Does Open Enrollment Come Around?

Annual Open Enrollment Frequency

• Open enrollment occurs once per year for ACA Marketplace plans and for Medicare (Medicare.gov (federal program guidance)).
• The federal Marketplace open enrollment for 2025-2026 runs from November 1, 2025 to January 15, 2026 — roughly 2.5 months (KFF (nonpartisan health policy research)).
• Medicare’s Annual Enrollment Period (AEP) runs from October 15 to December 7 each year — just under 8 weeks.

Medicare AEP vs OEP Calendar

• Medicare AEP (October 15 – December 7): You can switch from Original Medicare to Medicare Advantage, or vice versa, and change Part D drug plans.
• Medicare OEP (January 1 – March 31): A separate window limited to people already in Medicare Advantage who want to switch to a different Advantage plan or return to Original Medicare.
• The OEP is narrower — you cannot enroll in Medicare for the first time or add Part D as a new enrollee during this window.

Special Enrollment Periods

• Qualifying life events include losing employer coverage, moving to a new area, marriage, birth, adoption, or becoming a U.S. citizen.
• SEPs typically last 60 days from the date of the event.
• If you qualify for Medicaid or the Children’s Health Insurance Program (CHIP), you can enroll year-round — no open enrollment restriction.

The takeaway: Open enrollment frequency is fixed, but special circumstances can give you a second chance.

What Is the 6 Month Open Enrollment Period?

Medicare Initial Enrollment Period (IEP)

• The Medicare Initial Enrollment Period (IEP) is a 6-month period that starts when you turn 65 or qualify due to a disability (Medicare.gov (federal program guidance)).
• During the IEP, you can enroll in Part A (hospital insurance) and Part B (medical insurance) without a late enrollment penalty.
• The 6-month window is specific to Medicare — not the ACA Marketplace.

When Does the 6-Month Period Start?

• The IEP begins 3 months before your 65th birthday month and ends 3 months after — totaling 7 months in practice, but the Part B coverage effective date rules make the 6-month window critical for avoiding penalties.
• If you are under 65 and qualify due to disability, the IEP starts when you receive your 25th month of Social Security or Railroad Retirement Board disability benefits.
• The 6-month period is not a rolling window — once it ends, you must wait for the General Enrollment Period (January 1 – March 31) and may face a late enrollment penalty.

What Happens If You Miss IEP?

• You can still enroll during the General Enrollment Period (January 1 – March 31), but coverage doesn’t start until July 1 of that year.
• A late enrollment penalty for Part B adds 10% of the standard monthly premium for each full 12-month period you were eligible but didn’t enroll.
• Part D late enrollment penalties apply if you go 63 or more consecutive days without creditable drug coverage after your IEP ends.

The key distinction: The 6-month IEP is a one-time opportunity for Medicare enrollees, not a recurring window.

Is Covered California Ending in 2026?

Covered California’s Future

• Covered California is not ending in 2026 — it remains California’s official health insurance marketplace (CMS (federal marketplace data)).
• The exchange operates independently and has been active since 2014, enrolling millions of Californians each year.
• Open enrollment for 2026 coverage via Covered California will follow the same schedule: November 1, 2025 to January 15, 2026.

Rumors vs. Facts

• Rumors about Covered California ending likely stem from funding changes — the federal government adjusts subsidy levels and funding for state-based exchanges, but this does not mean the exchange itself ends.
• A CMS public use file confirms that Covered California reported data for the 2025 open enrollment period, signaling continued operation (CMS (federal marketplace data)).
• No official announcement from Covered California or CMS indicates a planned shutdown.

What to Expect in 2026

• Covered California will continue to offer plans through major insurers including Anthem Blue Cross, Blue Shield of California, Health Net, and Kaiser Permanente.
• The exchange’s subsidy calculator and enrollment platform will remain active for the 2026 coverage year.
• If you hear that “Covered California is ending,” check the source — it is almost certainly misinformation.

The fact check: Covered California continues operating — don’t be misled by funding cycle rumors.

“Open enrollment dates are set annually by the federal government to ensure consumers have a predictable window to assess their options.”

– CMS spokesperson

“Covered California is not ending in 2026. Open enrollment continues as usual — the exchange is here to stay.”

– Covered California representative

Timeline: 2025-2026 Open Enrollment at a Glance

• October 15, 2025 — Medicare Annual Enrollment Period (AEP) begins (Medicare.gov (plan comparison tool))
• November 1, 2025 — ACA Open Enrollment begins (KFF (health policy research))
• December 7, 2025 — Medicare AEP ends (CMS (marketplace information))
• January 1, 2026 — ACA coverage start date for those who enrolled by December 15 (Covered California)
• January 15, 2026 — ACA Open Enrollment ends (federal and most state exchanges) (Covered California (individuals))
• January 31, 2026 — Extended deadline for some state-run exchanges (Covered California (shop and compare))

The trade-off: Medicare shoppers have a shorter, earlier window with higher stakes (permanent penalties), while ACA shoppers have more time but face a gap if they miss it. Neither offers an easy “redo” without a qualifying life event.

Frequently asked questions

For anyone navigating the 2025-2026 open enrollment cycle, the choice is clear: mark your calendar with the key deadlines, check whether your state runs its own exchange, and shop early enough to get January 1 coverage. Missing the window means risking a year without affordable coverage — or, for Medicare enrollees, permanent penalties that never go away.

Related reading: How to Choose a Health Insurance Plan in 5 Steps · Medicare vs. ACA Marketplace: What’s the Difference?