Medicare open enrollment and ACA Marketplace dates

These are two different enrollments

Medicare and the Health Insurance Marketplace are not the same program, and they do not share one deadline.

• If you have Medicare, use Medicare.gov. The yearly Open Enrollment for Medicare health and drug plans is October 15 to December 7.
• If you need a Marketplace plan, use HealthCare.gov. Open Enrollment is November 1 to January 15. December 15 is the last day to enroll or change plans for coverage that starts January 1. You also have to pay your first premium.

Job-based plans can have their own open enrollment. Ask your employer. This guide does not cover those dates.

Medicare: October 15 to December 7

Medicare.gov says Open Enrollment happens each year from October 15 to December 7. Changes you make then start on January 1 of the next year. The plan must get your enrollment request by December 7.

What you can do depends on the coverage you have now. Medicare’s enrollment fact sheet says that during this window you can:

• Join, drop, or switch to another Medicare Advantage Plan, or add or drop drug coverage.
• Switch from Original Medicare to a Medicare Advantage Plan, or switch from a Medicare Advantage Plan to Original Medicare.
• Join, drop, or switch to another Medicare drug plan if you are in Original Medicare.

If you have looked at your options and you want to keep your current coverage, you do not have to do anything. Medicare says it continues on its own. Still read your plan’s notices. Costs, benefits, and which doctors are in the plan can change. If you stay, those changes also start on January 1.

A simple Medicare calendar

• October 1. Get ready. Read any notice from your current plan about next year’s costs and benefits. You can preview plans at Medicare.gov/plan-compare.
• October 15. Open Enrollment starts. You can join, switch, or drop a Medicare Advantage Plan or a Medicare drug plan, or switch to Original Medicare.
• December 7. Open Enrollment ends. In most cases this is the last day to change Medicare coverage for next year. A health or drug plan must get your enrollment form by December 7.
• January 1. New coverage starts if you switched. If you kept your plan, benefit and cost changes for the new year also start January 1.

How to make a Medicare change

1. Compare plans at Medicare.gov/plan-compare.
2. To join, select Enroll for the plan you want on that site, use the plan’s own website, or call the plan. You can also ask the plan for a paper form.
3. Make sure the plan has your request by December 7.

Official Medicare information is Medicare.gov, the Medicare & You handbook, and 1-800-MEDICARE (1-800-633-4227). TTY: 1-877-486-2048. Medicare says those are the official sources of unbiased Medicare information. Around this season you may get a lot of mail and ads. Start with Medicare.gov, not with an ad.

If you switch to Original Medicare, you may need a separate drug plan. You may also want Medicare Supplement Insurance, called Medigap. That is extra insurance you can buy from a private company to help pay your share of Original Medicare costs. Medicare says there are limits on when you can add it. Read the rules on Medicare’s Medigap page before you count on it.

Do not mix this up with Medicare Advantage Open Enrollment

That is a second window, and it is narrower.

• If you are already in a Medicare Advantage Plan, it runs January 1 to March 31.
• If you are new to Medicare and joining a Medicare Advantage Plan, Medicare says this period runs from the first month you have both Part A and Part B until the last day of the third month you have both.
• You can make one change during the year in this window.
• You can switch to another Medicare Advantage Plan, with or without drug coverage.
• You can drop your Medicare Advantage Plan and return to Original Medicare. If you do that, you can join a Medicare drug plan.
• You cannot use this window to move from Original Medicare into a Medicare Advantage Plan.
• You cannot use it to join a Medicare drug plan if you are already in Original Medicare, or to switch from one drug plan to another while you are in Original Medicare.
• The change starts on the first day of the month after the plan gets your request.

People who are new to Medicare also have an Initial Enrollment Period. Those dates depend on your situation. They are in Medicare’s fact sheet, Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods.

Marketplace: November 1 to January 15

HealthCare.gov says the yearly Marketplace Open Enrollment Period is November 1 to January 15. On October 21, 2026, its dates page said that starting November 1 you can apply for 2027 coverage, or update your application with changes you expect for the year ahead.

• November 1. Open Enrollment starts. This is the first day you can enroll in, renew, or change a Marketplace plan for the coming year. Coverage can start as soon as January 1.
• December 15. Last day to enroll in or change plans for coverage that starts January 1.
• January 1. Coverage starts if you enrolled or changed plans by December 15 and paid your first premium.
• January 15. Open Enrollment ends. This is the last day to enroll in or change Marketplace plans for the year. After this date, you can enroll or change plans only if you qualify for a Special Enrollment Period.
• February 1. Coverage starts if you enrolled or changed plans from December 16 through January 15 and paid your first premium.

You must pay the first premium or coverage does not start.

Update your application before you enroll

Marketplace savings are based on the income and household you expect for the year you want coverage, not on a past year. HealthCare.gov says that if you do not update:

• You could qualify for more savings than you are getting now.
• You could qualify for less savings and have to pay the difference when you file your federal taxes.

If you do nothing by December 15, you may be automatically re-enrolled for January 1 coverage. You should still update your application so the savings amount is right. In some cases you will not be automatically re-enrolled. If that is you, enroll during Open Enrollment to keep Marketplace coverage for next year.

How to enroll in a Marketplace plan

1. See whether your state uses HealthCare.gov or its own Marketplace. Pick your state at The Marketplace in your state. HealthCare.gov says that starting November 1, Oregon residents will use ExploreHealthOR.gov to enroll in 2027 coverage, and should keep using HealthCare.gov for 2026 coverage information.
2. Create or open your account, update your income and household, and compare plans. HealthCare.gov says you can preview plans and prices while you get ready.
3. Enroll by December 15 if you want coverage to start January 1. Pay the first premium.
4. If you miss December 15, you can still enroll through January 15. Coverage then starts February 1, if you pay the first premium.

You can apply online, by phone, with local help, or with a paper application. The Marketplace Call Center for individuals and families, including self-employed people, is 1-800-318-2596 (TTY: 1-855-889-4325). It is open 24 hours a day, 7 days a week, except holidays. The number is on the HealthCare.gov contact page.

If you miss January 15

After Open Enrollment, Marketplace plans are available only if you qualify for a Special Enrollment Period. HealthCare.gov gives examples of life events that can qualify: moving, losing other coverage, getting married, or having a baby.

You can apply for Medicaid or the Children’s Health Insurance Program (CHIP) at any time of year.

Which site should you use?

Use Medicare.gov if the question is about Medicare Advantage, a Medicare drug plan, or Original Medicare.

Use HealthCare.gov, or your state’s Marketplace if HealthCare.gov sends you there, if the question is about a private Marketplace plan.

If you are not sure which program you have, look at your insurance card and the latest letter from the plan. Then call 1-800-MEDICARE or the Marketplace Call Center. Do not rely on a phone number printed in an advertisement.