Medicare Open Enrollment 2027: Dates, Deadlines and What You Can Change

Medicare Open Enrollment gives people with Medicare an annual opportunity to review their coverage and make certain changes for the following year. For 2027 coverage, Medicare Open Enrollment runs from October 15 through December 7, 2026.

Quick answer: During Medicare Open Enrollment, you can make certain changes involving Original Medicare, Medicare Advantage and Medicare Part D prescription drug coverage. Changes made during this period generally take effect January 1, 2027.

For a broader overview of Medicare coverage, costs, plan options and enrollment, see our complete guide to Medicare in California.

When Is Medicare Open Enrollment for 2027?

Medicare Open Enrollment takes place every year from:

October 15 through December 7

For coverage beginning in 2027, that means Medicare Open Enrollment runs from October 15, 2026 through December 7, 2026.

Changes made during this enrollment period generally take effect on January 1, 2027.

What Is Medicare Open Enrollment?

Medicare Open Enrollment is an annual period when people who already have Medicare can make certain changes to their Medicare coverage.

Depending on your current coverage and eligibility, you may be able to:

• Switch from Original Medicare to a Medicare Advantage plan
• Switch from Medicare Advantage back to Original Medicare
• Change from one Medicare Advantage plan to another
• Join a Medicare Part D prescription drug plan
• Change from one Part D plan to another
• Drop Medicare Part D coverage

The changes available to you depend on your current Medicare coverage and individual circumstances.

When Do Open Enrollment Changes Take Effect?

Changes made during Medicare Open Enrollment generally take effect on January 1 of the following year.

For example, if you change Medicare coverage during the October 15 through December 7, 2026 Open Enrollment Period, the new coverage generally begins January 1, 2027.

Your current coverage generally continues through December 31, 2026 unless another applicable enrollment rule affects your coverage.

Why Should You Review Your Medicare Coverage Each Year?

Medicare Advantage and Medicare Part D plans can change from year to year.

Changes may affect:

• Monthly premiums
• Deductibles
• Copayments and coinsurance
• Provider networks
• Prescription drug formularies
• Drug tiers
• Pharmacy networks
• Additional benefits
• Prior authorization requirements

Your own health care needs can also change. A plan that worked for you during one year may work differently the following year because of changes to the plan, your prescriptions, your doctors or your health care needs.

What Is an Annual Notice of Change?

If you are enrolled in a Medicare Advantage or Medicare Part D plan, your plan generally sends an Annual Notice of Change, often called an ANOC.

This notice explains important changes to the plan for the upcoming year.

The Annual Notice of Change may describe changes involving:

• Premiums
• Deductibles
• Copayments and coinsurance
• Benefits
• Prescription drug coverage
• Other plan rules

Reviewing this document can help you understand how your existing coverage will change if you remain enrolled for 2027.

Can You Switch Medicare Advantage Plans During Open Enrollment?

Yes. During the October 15 through December 7 Medicare Open Enrollment Period, eligible beneficiaries can switch from one Medicare Advantage plan to another Medicare Advantage plan.

When comparing plans, review more than the monthly premium.

Important differences can include:

• Whether your doctors and hospitals participate in the plan's network
• Prescription drug coverage
• Copayments and coinsurance
• Annual out-of-pocket limits
• Prior authorization requirements
• Additional benefits

Can You Switch From Original Medicare to Medicare Advantage?

During Medicare Open Enrollment, eligible people with Original Medicare can enroll in a Medicare Advantage plan for the following year.

Medicare Advantage, also known as Medicare Part C, is an alternative way to receive Medicare Part A and Part B benefits through a private insurance company that contracts with Medicare.

Most Medicare Advantage plans also include Medicare Part D prescription drug coverage.

Before changing coverage, it is important to understand differences involving provider access, prescription coverage, costs and plan rules.

See our guide to Original Medicare vs. Medicare Advantage for a detailed explanation.

Can You Switch From Medicare Advantage Back to Original Medicare?

Yes. During Medicare Open Enrollment, you can generally leave a Medicare Advantage plan and return to Original Medicare.

If you return to Original Medicare, you may also need to consider separate Medicare Part D prescription drug coverage.

It is also important to understand that returning to Original Medicare does not necessarily guarantee that you can purchase any Medicare Supplement, or Medigap, policy you want.

Medigap has separate enrollment rules and protections that should be reviewed before making a coverage change.

Learn more in our guide to Medicare Advantage vs. Medicare Supplement (Medigap).

Can You Change Medicare Part D Plans?

Yes. Medicare Open Enrollment is an opportunity for eligible beneficiaries to review and change Medicare Part D prescription drug coverage.

Part D plans can change their:

• Formularies
• Drug tiers
• Premiums
• Deductibles
• Copayments and coinsurance
• Pharmacy networks

Your medications can also change during the year, so reviewing your current prescriptions against the plan's coverage for 2027 can be important.

See our guide to Medicare Part D and prescription drug coverage.

What Should You Review Before December 7?

Before the Medicare Open Enrollment deadline, consider reviewing:

• Your current Medicare coverage
• Your plan's Annual Notice of Change
• Your monthly premium
• Your doctors and hospitals
• Your prescription medications
• Your pharmacy
• Your deductibles and cost-sharing
• Your plan's annual out-of-pocket limit, if applicable
• Any changes to benefits for 2027

Reviewing these items can help you understand how your existing coverage compares with the coverage available for the upcoming year.

What Happens if You Do Nothing During Medicare Open Enrollment?

If your current Medicare Advantage or Part D plan continues to be offered and you remain eligible for it, your coverage will generally renew automatically for the following year if you do not make a change.

However, the plan's costs, benefits, provider network, formulary or other features may change for the new year.

Automatic renewal therefore does not necessarily mean your coverage will remain exactly the same.

Is Medicare Open Enrollment the Same as Initial Enrollment?

No.

The Initial Enrollment Period is generally the period when someone first becomes eligible for Medicare.

For most people becoming eligible at age 65, the Initial Enrollment Period lasts seven months, beginning three months before the month they turn 65 and ending three months after their birthday month.

The annual Medicare Open Enrollment Period from October 15 through December 7 is primarily for people who already have Medicare and want to make certain coverage changes for the following year.

See Medicare Enrollment: When and How to Sign Up for Medicare for more information.

Is Medicare Open Enrollment the Same as Medigap Open Enrollment?

No. These are separate enrollment periods.

Medicare Open Enrollment runs from October 15 through December 7 each year and involves changes to Medicare Advantage and Medicare prescription drug coverage, as well as certain changes between Medicare Advantage and Original Medicare.

Your federal Medigap Open Enrollment Period is generally a one-time six-month period that begins when you are age 65 or older and enrolled in Medicare Part B.

The annual October 15 through December 7 Medicare Open Enrollment Period does not create a new federal Medigap Open Enrollment Period.

What Is the Medicare Advantage Open Enrollment Period?

There is another enrollment period specifically for people who are already enrolled in a Medicare Advantage plan.

The Medicare Advantage Open Enrollment Period runs from January 1 through March 31 each year.

During this period, someone already enrolled in Medicare Advantage can generally:

• Switch to another Medicare Advantage plan
• Leave Medicare Advantage and return to Original Medicare

If you return to Original Medicare during this period, you may also be able to join a separate Medicare Part D plan.

You generally cannot use the Medicare Advantage Open Enrollment Period to switch from Original Medicare into Medicare Advantage.

Are There Other Times You Can Change Medicare Coverage?

Yes. Certain circumstances may qualify you for a Medicare Special Enrollment Period.

Special Enrollment Periods can apply after certain life events or changes in coverage, such as moving outside a plan's service area or losing certain types of coverage.

The changes you can make and the amount of time available depend on the specific Special Enrollment Period.

What if You're New to Medicare in 2027?

If you are becoming eligible for Medicare for the first time, the October 15 through December 7 Open Enrollment Period may not be the primary enrollment period that determines when you should initially sign up.

Your Initial Enrollment Period or another applicable enrollment period may determine your Medicare enrollment deadlines.

If Medicare is new to you, start with New to Medicare: A Beginner’s Guide to Medicare Parts A, B, C and D.

Medicare Open Enrollment 2027 Checklist

Before making any Medicare coverage changes for 2027, consider checking:

• Are your doctors and hospitals still participating?
• Are your prescriptions still covered?
• Have any medications moved to different tiers?
• Has the monthly premium changed?
• Have deductibles or copayments changed?
• Has the pharmacy network changed?
• Have additional benefits changed?
• Have prior authorization requirements changed?
• Do you understand when any new coverage will begin?

Frequently Asked Questions

When is Medicare Open Enrollment for 2027?

Medicare Open Enrollment for 2027 coverage runs from October 15 through December 7, 2026.

When do changes made during Medicare Open Enrollment take effect?

Changes made during the October 15 through December 7 Open Enrollment Period generally take effect January 1 of the following year. For the 2027 coverage year, changes generally take effect January 1, 2027.

Can I change Medicare Advantage plans during Open Enrollment?

Yes. Eligible beneficiaries can switch from one Medicare Advantage plan to another during the annual Medicare Open Enrollment Period.

Can I leave Medicare Advantage and return to Original Medicare?

Yes. Medicare Open Enrollment allows eligible beneficiaries to leave Medicare Advantage and return to Original Medicare. Separate rules apply to Medicare Part D and Medigap coverage.

Can I change my Medicare Part D plan?

Yes. Medicare Open Enrollment allows eligible beneficiaries to change Medicare Part D prescription drug plans for the following year.

What happens if I don't change my Medicare plan?

If your current plan continues to be offered and you remain eligible, your coverage will generally renew automatically. However, the plan's costs, benefits, provider network or prescription drug coverage may change for the new year.

Is Medicare Open Enrollment the same as Medigap Open Enrollment?

No. Medicare Open Enrollment and Medigap Open Enrollment are separate periods with different purposes and rules.

What is the Medicare Open Enrollment deadline?

The annual Medicare Open Enrollment deadline is December 7.

This article is for general educational and informational purposes. Medicare enrollment periods, benefits, costs, provider networks, formularies and plan availability can vary based on individual circumstances and may change over time. For official Medicare information, visit Medicare.gov or call 1-800-MEDICARE.