Medicare Advantage Open Enrollment 2027: Dates, Plan Changes and How to Switch

If you’re already enrolled in a Medicare Advantage plan, the Medicare Advantage Open Enrollment Period for 2027 runs from January 1 through March 31, 2027. During this period, you can generally make one change: switch to another Medicare Advantage plan, or leave Medicare Advantage and return to Original Medicare. If you return to Original Medicare, you can also join a separate Medicare drug plan. Any change generally takes effect on the first day of the month after the plan receives your request.

There is an important distinction, though. If you’re trying to choose or change coverage for the 2027 plan year before January 2027, the main Medicare Open Enrollment Period, also called the Annual Enrollment Period (AEP), is October 15 through December 7, 2026. Changes made during that period generally take effect January 1, 2027.

That means “Medicare Advantage open enrollment 2027” can refer to two closely related but different periods. Knowing which one applies to you can prevent missed deadlines and an unnecessary change in coverage.

Important: This article provides general Medicare education. Medicare Advantage premiums, provider networks, formularies, benefits, plan availability, and enrollment options can vary by plan, county, and individual circumstances. Review official Medicare information and your plan documents before making a coverage decision.

Medicare Advantage Enrollment Dates for 2027

Here are the most important dates to know when preparing for 2027 coverage:

Medicare’s official guidance confirms that the October 15–December 7 period is the annual Open Enrollment Period, while the January 1–March 31 Medicare Advantage Open Enrollment Period is available to people already enrolled in Medicare Advantage. Special Enrollment Periods have different eligibility rules and dates depending on the situation.

AEP vs. MA OEP: What’s the difference?

The easiest way to remember the distinction is:

AEP is the main period for choosing 2027 coverage.

MA OEP is a limited opportunity to change your Medicare Advantage coverage after the year has started.

During AEP, Medicare beneficiaries can make a broader range of permitted coverage changes, including switching Medicare Advantage plans, moving between Original Medicare and Medicare Advantage, and making eligible prescription-drug coverage changes. During MA OEP, an existing Medicare Advantage enrollee can make only one permitted change.

If you’re currently enrolled in Medicare Advantage and are considering a 2027 switch, it is usually better to review your options before AEP ends rather than relying on the MA OEP later.

Who Can Use the Medicare Advantage Open Enrollment Period?

The MA OEP is primarily for people who are already enrolled in a Medicare Advantage plan.

From January 1 through March 31, an eligible Medicare Advantage enrollee can:

• Switch to another Medicare Advantage plan, with or without drug coverage.
• Leave Medicare Advantage and return to Original Medicare.
• Join a separate Medicare drug plan after returning to Original Medicare.

You can make only one change during the Medicare Advantage Open Enrollment Period.

There is also a related rule for people who are newly enrolled in Medicare. Someone who joins a Medicare Advantage plan during their Initial Enrollment Period may have an opportunity during the first three months they have both Part A and Part B to change to another Medicare Advantage plan or return to Original Medicare. This is distinct from the regular January–March MA OEP for existing enrollees.

What Can You Change During Medicare Advantage Open Enrollment?

The MA OEP is more limited than the annual fall enrollment period.

You can switch Medicare Advantage plans

You can move from one Medicare Advantage plan to another, whether the new plan includes prescription drug coverage or not.

This can make sense when your current plan’s 2027 costs, provider network, formulary, or benefits no longer fit your needs.

You can leave Medicare Advantage

You can disenroll from Medicare Advantage and return to Original Medicare. If you do this, you can also join a standalone Medicare Part D plan for prescription drug coverage.

You cannot use the MA OEP for unlimited changes

The MA OEP allows one change. It is not a period where you can repeatedly switch between Medicare Advantage plans throughout January, February, and March.

You also cannot use the MA OEP simply to move from Original Medicare into a Medicare Advantage plan. That type of change belongs to other enrollment opportunities, including the annual Open Enrollment Period.

When Does a Medicare Advantage Switch Take Effect?

Timing matters because the date you submit a request is not necessarily the date your new coverage begins.

For a change made during the MA OEP, the new coverage generally starts on the first day of the month after the plan receives your request.

For example, if a new plan receives your request on:

These examples illustrate the general timing rule. Your actual effective date can depend on the enrollment circumstances and the plan’s receipt of your request, so confirm the date with Medicare or the plan.

Should You Switch Medicare Advantage Plans in January?

A January switch can make sense when you discover that your current coverage does not meet your needs after the new year begins.

Common reasons to reconsider a plan include:

• Your preferred doctor or hospital is no longer in the network.
• A medication has moved to a less favorable formulary tier or is subject to new restrictions.
• Your premium, copays, deductible, or other cost-sharing changed.
• A supplemental benefit you relied on has changed.
• The plan’s rules or network structure no longer fit how you use healthcare.

Medicare recommends checking whether your doctors and pharmacies are in the plan’s network, whether your prescriptions are covered, and what premiums, deductibles, and other costs apply before choosing coverage.

The MA OEP can provide a second opportunity for an existing Medicare Advantage member who realizes the current plan is not working as expected. But because only one change is allowed, comparing the replacement plan carefully is important.

How to Switch Medicare Advantage Plans in 2027

The mechanics are straightforward, but the research beforehand is where most of the decision-making happens.

1. Review your current plan

Start with the documents your plan sends for the upcoming year.

The Annual Notice of Change (ANOC) is sent each fall and explains changes to coverage, costs, and other plan details that take effect in January. The Evidence of Coverage (EOC) provides more detailed information about what the plan covers, what you pay, and the rules that apply.

A useful approach is to use the ANOC to identify what changed and then use the EOC to investigate the details.

2. Check your doctors and hospitals

A Medicare Advantage provider network can be one of the most important factors in a plan decision.

Before switching, verify:

• Primary-care doctor
• Specialists
• Preferred hospital
• Major medical group
• Outpatient facilities
• Other providers you use regularly

Medicare specifically advises beneficiaries to check whether their doctors and pharmacies are in the plan’s network.

Don’t assume that because a doctor accepted your current Medicare Advantage plan, the doctor will automatically participate in another plan.

3. Check your prescription drugs

If your Medicare Advantage plan includes prescription drug coverage, review the new plan’s drug formulary before enrolling.

Look at:

• Whether each medication is covered
• The drug’s tier
• Copayment or coinsurance
• Prior authorization requirements
• Quantity limits
• Step therapy
• Preferred pharmacies

Medicare’s plan-comparison tools allow users to enter prescriptions and pharmacies to estimate plan costs.

For someone taking several medications, this step can be more important than choosing a plan based on its monthly premium alone.

4. Compare the total cost, not just the premium

Medicare Advantage costs vary by plan.

Your comparison should include:

• Monthly plan premium
• Medicare Part B premium obligation
• Deductible
• Primary-care copays
• Specialist copays
• Hospital cost-sharing
• Prescription costs
• Annual medical out-of-pocket maximum

Medicare states that Medicare Advantage premiums and other costs vary by plan, while the annual out-of-pocket limit also varies by plan. Once a plan member reaches the applicable limit for covered Medicare Part A and Part B services, the plan generally pays 100% of covered services for the rest of the calendar year.

A plan with a $0 additional premium is not automatically the lowest-cost choice for every person. Expected healthcare use, prescriptions, provider access, and cost-sharing can change the overall picture.

5. Review supplemental benefits

Medicare Advantage plans may offer benefits beyond Original Medicare, such as dental, vision, hearing, and other supplemental benefits.

Don’t compare these benefits using the headline amount alone.

Check:

• What services are covered
• Annual limits
• Copayments or coinsurance
• Provider requirements
• Eligibility rules
• Whether the benefit uses a separate network
• Any authorization requirements

CMS has also finalized 2027 rules affecting certain supplemental-benefit administration and transparency. For some Special Supplemental Benefits for the Chronically Ill, plans must publicly post their plan-developed eligibility criteria.

The benefit that matters most is the one you can actually use under the plan’s rules.

How to Use Medicare Plan Finder for a 2027 Comparison

Medicare’s official Plan Finder allows beneficiaries to enter their ZIP code and compare Medicare Advantage, drug, and other Medicare coverage options available in their area. For 2027, the tool includes 2027 plan information, and logged-in users can save their prescriptions and pharmacies to help compare estimated costs.

Open Medicare Plan Finder

When comparing Medicare Advantage plans, don’t stop at the first attractive premium.

Use a consistent checklist:

Plan availability → premium → deductible → doctor network → hospital network → prescription formulary → pharmacy network → out-of-pocket maximum → dental/vision/hearing → other supplemental benefits.

That approach makes it easier to compare plans based on the coverage you actually use.

What Is Changing With Medicare Advantage in 2027?

The 2027 Medicare Advantage market remains broad, but availability is still location-specific.

CMS’s September 28, 2026 announcement projects approximately 5,532 Medicare Advantage plans nationally for 2027, compared with 5,553 in 2026. CMS also says more than 99% of Medicare beneficiaries are projected to have access to at least one Medicare Advantage plan, while 97% are projected to have access to 10 or more choices.

Those national figures do not tell you which plans are available in your county.

For an overview of federal program changes and broader 2027 developments, see the Smart Insurance Reviews guide:

Medicare Advantage Changes in 2027

The practical takeaway is that your exact plan documents and local plan availability matter more than a national average.

What If Your Medicare Advantage Plan Is Discontinued for 2027?

A plan being discontinued or nonrenewed is different from an ordinary decision to switch plans.

If a Medicare Advantage plan’s contract with Medicare is not renewed, Medicare provides a Special Enrollment Period that gives affected beneficiaries an opportunity to select other coverage. For a nonrenewed Medicare Advantage plan, the relevant SEP generally runs from December 8 through the last day of February of the following year. If the beneficiary does not join another Medicare Advantage plan before the current plan ends, Medicare says they will be enrolled in Original Medicare.

Different rules can apply when a contract ends for another reason, so the specific notice you receive matters.

If your plan is ending, check these items immediately:

1. Confirm that your plan is actually being terminated or nonrenewed.
2. Review the replacement plans available in your county.
3. Check your prescription formulary.
4. Verify your doctors and hospital.
5. Compare premiums and cost-sharing.
6. Review the out-of-pocket maximum.
7. Check dental, vision, hearing, OTC, food, transportation, and other benefits that matter to you.

An Annual Notice of Change is not the same thing as a nonrenewal notice, so read the plan communication carefully.

Can You Switch Medicare Advantage Plans After Open Enrollment?

Usually, the answer depends on which enrollment period you mean and whether you qualify for another election opportunity.

After the December 7 AEP deadline, an existing Medicare Advantage member may generally use the MA OEP from January 1 through March 31 to make one permitted change. After March 31, the MA OEP has ended, but certain people may qualify for a Special Enrollment Period based on a qualifying circumstance.

Examples of circumstances that may create an SEP include:

• Moving to a new address
• Losing other health coverage
• A Medicare Advantage plan ending or not being renewed
• Certain changes involving Medicaid or Extra Help
• Certain exceptional circumstances
• Living in an area with an available 5-star Medicare plan

SEP rules vary according to the event, including the date the opportunity begins and ends.

If you think a special circumstance applies to you, verify the specific SEP rather than assuming the ordinary MA OEP dates apply.

What Happens if You Leave Medicare Advantage for Original Medicare?

Switching back to Original Medicare is different from simply moving to another Medicare Advantage plan.

When you return to Original Medicare, you may need a separate Medicare Part D prescription drug plan if you want prescription coverage. You may also consider Medigap, which can help pay certain out-of-pocket costs associated with Original Medicare.

One important issue is Medigap eligibility.

Federal law does not guarantee that everyone leaving Medicare Advantage can immediately purchase any Medigap policy without underwriting. Certain situations provide guaranteed issue rights, including specific trial-right circumstances and other qualifying events. State law may also provide additional protections.

That means someone considering a move from Medicare Advantage to Original Medicare should investigate Medigap eligibility and timing before making the switch, rather than assuming a Medigap policy will automatically be available on the same terms.

For a broader explanation of the differences between these coverage structures, see:

Medicare Advantage vs. Medigap

Medicare Advantage 2027 Switching Checklist

Before submitting an enrollment request, use this checklist:

Your doctors and healthcare

• Is my primary-care doctor still in-network?
• Are my specialists included?
• Is my preferred hospital covered?
• Are the facilities I regularly use in-network?
• Are referral or network rules different?

Your prescriptions

• Are all of my medications covered?
• Did any drug move to a different tier?
• What are the copays or coinsurance?
• Does the plan require prior authorization or step therapy?
• Is my preferred pharmacy still in-network?

Your costs

• What is the monthly premium?
• What deductible applies?
• What will I pay for the services I use most?
• What is the annual medical out-of-pocket maximum?
• What could my prescription costs look like over the year?

Your extra benefits

• Did dental coverage change?
• What vision benefits are included?
• What hearing benefits are included?
• Are OTC or healthy-food benefits changing?
• Are there new eligibility restrictions?
• Are transportation or other supplemental benefits still available?

Your enrollment status

• Am I comparing during AEP or MA OEP?
• Am I allowed to make the change I want?
• Do I have another Special Enrollment Period?
• When will my new coverage become effective?
• Have I received and reviewed my ANOC and EOC?

Common Mistakes to Avoid During Medicare Advantage Open Enrollment 2027

Focusing only on the monthly premium

A low premium does not necessarily mean lower total annual spending. Compare the cost-sharing structure and the healthcare services and prescriptions you actually use.

Assuming your doctor will remain in-network

Provider networks are plan-specific. Verify doctors, specialists, hospitals, and other important providers before changing plans.

Ignoring the drug formulary

A plan can look attractive until prescription coverage is checked. Review each medication, its tier, restrictions, and pharmacy options.

Treating supplemental benefits as guaranteed Medicare benefits

Dental, vision, hearing, food, OTC, transportation, and similar benefits can differ between plans and may have limits or eligibility requirements.

Waiting until the last possible date

Waiting can leave less time to compare plans, understand documents, and verify your medications and providers.

Assuming AEP and MA OEP are interchangeable

They are not. AEP and MA OEP have different dates, eligibility rules, and permitted changes.

The Bottom Line

For Medicare Advantage Open Enrollment 2027, the first thing to establish is which enrollment period applies to your situation.

For coverage changes taking effect in 2027, the main Annual Enrollment Period is October 15 through December 7, 2026. For people already enrolled in Medicare Advantage, the Medicare Advantage Open Enrollment Period runs January 1 through March 31, 2027, and generally allows one change.

The smartest way to evaluate a potential switch is to look beyond the premium. Review your ANOC and EOC, verify doctors and hospitals, check your prescription formulary and pharmacy network, compare total costs and the medical out-of-pocket maximum, and examine the supplemental benefits you actually use. Medicare’s Plan Finder can help you compare plan availability, estimated costs, prescriptions, and pharmacies in your area.

And remember: a national Medicare Advantage statistic is not a substitute for reviewing your own 2027 plan. Plan availability, benefits, costs, networks, and formularies can vary by location and plan.

For additional 2027 Medicare research, Smart Insurance Reviews also covers [Medicare Part D changes in 2027] through its broader coverage analysis.

Medicare Part D Changes in 2027

Frequently Asked Questions

When is Medicare Advantage Open Enrollment for 2027?

The Medicare Advantage Open Enrollment Period for 2027 runs from January 1 through March 31, 2027. It is primarily for people already enrolled in Medicare Advantage and generally allows one permitted change.

What is the difference between AEP and MA OEP?

The annual Open Enrollment Period (AEP) is October 15 through December 7, 2026, for making permitted coverage changes for 2027. The Medicare Advantage Open Enrollment Period (MA OEP) is January 1 through March 31, 2027, and gives eligible Medicare Advantage members one opportunity to make a permitted change.

Can I switch Medicare Advantage plans in January 2027?

Generally, yes, if you are enrolled in Medicare Advantage and otherwise eligible to use the MA OEP. You can switch to another Medicare Advantage plan during January, February, or March, but you can make only one change during the period.

When does a Medicare Advantage plan switch take effect?

During the MA OEP, the new coverage generally starts on the first day of the month after the plan receives your request.

Can I switch Medicare Advantage plans after March 31, 2027?

The MA OEP ends March 31. After that, you generally need another qualifying enrollment opportunity, such as a Special Enrollment Period, to make a change outside the regular annual periods. SEP eligibility depends on your specific circumstances.

What is an Annual Notice of Change?

An Annual Notice of Change (ANOC) is a document your Medicare plan sends each fall explaining changes to coverage, costs, and other plan details that will take effect in January.

What is an Evidence of Coverage document?

Evidence of Coverage (EOC) provides detailed information about what your Medicare plan covers, how much you pay, and the rules that apply to your coverage.

What should I check before switching Medicare Advantage plans?

At minimum, compare your doctors and hospitals, prescription formulary, pharmacy network, premiums, deductibles, copays, out-of-pocket maximum, and important supplemental benefits. Medicare recommends checking provider networks, prescriptions, and costs before enrolling.

What if my Medicare Advantage plan is discontinued for 2027?

If your plan’s Medicare contract is not renewed, you generally receive a Special Enrollment Period from December 8 through the last day of February of the following year to choose other coverage. The exact rules depend on why the coverage is ending.

Can I switch from Medicare Advantage to Original Medicare?

Yes. During the appropriate enrollment period, you can leave Medicare Advantage and return to Original Medicare. You may also enroll in a separate Part D drug plan. However, Medigap eligibility and guaranteed issue rights depend on your circumstances, so investigate those rules before switching.