Medicare Supplement Open Enrollment Explained

Medicare Supplement Open Enrollment is the six-month period when you have your strongest federal protections for purchasing Medicare Supplement insurance, also called Medigap.

For someone age 65 or older, this one-time enrollment period begins the first month the person is both:

• At least 65 years old
• Enrolled in Medicare Part B

During these six months, an insurance company cannot deny you an eligible Medicare Supplement policy, charge you more because of your health, or use medical underwriting to determine whether to accept your application.

This period is different from Medicare’s fall Annual Enrollment Period. It generally happens only once, and missing it can make purchasing or changing Medicare Supplement coverage more difficult later.

When Does Medicare Supplement Open Enrollment Begin?

For most people turning 65, Medicare Supplement Open Enrollment begins on the first day of the month their Medicare Part B coverage becomes effective.

For example, if your Medicare Part B coverage begins July 1, your six-month Medigap Open Enrollment Period ordinarily runs from July 1 through December 31.

The important date is the effective date of Medicare Part B—not the day you request information, compare plans, or submit a Medicare Supplement application.

If you delay Medicare Part B because you are continuing to work and have qualifying employer group coverage, your Medigap Open Enrollment Period generally does not begin until your Part B coverage becomes effective.

However, enrolling in Part B while keeping employer coverage ordinarily starts the six-month Medigap window. Keeping the employer plan does not pause or restart that period.

How Long Does Medicare Supplement Open Enrollment Last?

Medicare Supplement Open Enrollment lasts six months.

The six months begin with the first month you are both at least 65 and enrolled in Medicare Part B. The period does not begin on the date you purchase a Medicare Supplement policy.

It also does not end merely because you select a policy.

If you purchase a Medicare Supplement plan early in the six-month period, your remaining open-enrollment protection generally continues through the end of the original six months.

That can be important if you realize that another Medicare Supplement plan or insurance company would be more suitable before the period ends.

Do not wait until the final days to apply. An incomplete application or missing information can create unnecessary timing problems.

What Protections Do You Have During Medicare Supplement Open Enrollment?

During Medicare Supplement Open Enrollment, an insurance company must allow you to purchase any Medicare Supplement policy it sells for which you are otherwise eligible.

The company cannot use your health history to:

• Deny your application
• Refuse to sell you an eligible policy
• Charge you more because of a health condition
• Require you to qualify through medical underwriting
• Delay the entire policy’s effective date because of your health

You can generally compare available Medicare Supplement companies based on factors such as:

• Premium
• Standardized plan letter
• Household discounts
• Pricing method
• Company history
• Customer service
• Administrative reliability
• Available payment options

Your medical history should not limit your choices during this protected period.

Can a Medicare Supplement Company Ask Health Questions During Open Enrollment?

Yes. A Medicare Supplement application may contain health questions even when you are applying during your protected Open Enrollment Period.

You should answer every application question completely and accurately.

However, when you are protected by Medicare Supplement Open Enrollment, the insurance company cannot use your medical answers to:

• Deny your application
• Charge you a higher premium because of your health
• Refuse to sell you an eligible policy

Health information may still be relevant to a possible pre-existing-condition waiting period, eligibility verification, or other administrative requirements.

Never omit medical information simply because you are applying during Open Enrollment.

Can a Pre-Existing Condition Be Subject to a Waiting Period?

Possibly.

Medicare Supplement Open Enrollment prevents an insurance company from denying your application because of a pre-existing condition. However, it does not always prevent a temporary waiting period for coverage related to that condition.

A company may be permitted to delay coverage for a pre-existing condition for up to six months when:

• The condition was diagnosed or treated during the six months before the policy began
• You did not have sufficient prior creditable coverage
• No other rule prohibits the waiting period

The Medicare Supplement policy can still cover other eligible medical expenses during that time. Original Medicare also continues paying its portion of Medicare-covered services.

Prior creditable coverage may reduce or eliminate the waiting period. If you had at least six months of continuous creditable coverage before purchasing the policy, a new pre-existing-condition waiting period generally should not apply.

Creditable coverage can include certain:

• Employer group health plans
• Individual health insurance
• Medicare coverage
• Medicaid coverage
• Other qualifying health coverage

A break in coverage may affect how much prior coverage receives credit. Confirm any possible waiting period before the policy becomes effective.

Does Medicare Supplement Open Enrollment Happen Every Year?

No. Medicare Supplement Open Enrollment is generally a one-time six-month period.

It does not return every October.

This is one of the most common sources of confusion because Medicare uses similar names for several different enrollment periods.

Medicare’s October 15 through December 7 Annual Enrollment Period primarily allows beneficiaries to:

• Change Medicare Advantage plans
• Join or leave a Medicare Advantage plan
• Change Medicare Part D prescription drug plans
• Join or drop Medicare Part D coverage

The fall Annual Enrollment Period does not create a new Medicare Supplement Open Enrollment Period and does not automatically protect someone from Medigap medical underwriting.

Is Medicare Supplement Open Enrollment the Same as Medicare Initial Enrollment?

No. These are different enrollment periods.

Your Medicare Initial Enrollment Period is the seven-month window generally used to enroll in Medicare Part A and Part B around your 65th birthday.

It ordinarily includes:

• The three months before your 65th-birthday month
• Your birthday month
• The three months after your birthday month

Medicare Supplement Open Enrollment is the six-month period that begins when you are at least 65 and enrolled in Part B.

The periods may overlap, but they serve different purposes.

Your Initial Enrollment Period determines when you can enroll in Medicare. Your Medicare Supplement Open Enrollment Period determines when you receive your strongest federal protections for purchasing Medigap coverage.

What Happens if You Delay Medicare Part B?

Some people delay Medicare Part B because they or their spouse are actively working and they remain covered through a qualifying employer group health plan.

When Part B is properly delayed, Medicare Supplement Open Enrollment generally begins when the person later enrolls in Part B at age 65 or older.

For example, someone who works until age 68 and delays Part B may receive the six-month Medigap Open Enrollment Period when Part B begins at age 68.

Do not delay Part B solely to preserve Medicare Supplement Open Enrollment without confirming that the employer coverage permits a safe delay.

COBRA, retiree coverage, Marketplace coverage, and coverage from a small employer may not protect you from Medicare Part B penalties or gaps in the same way as active-employment group coverage.

Before delaying Part B, confirm the rules with the employer benefits administrator and Social Security.

What if You Enroll in Part B While Still Working?

If you are 65 or older and enroll in Medicare Part B while continuing to work, your six-month Medicare Supplement Open Enrollment Period generally begins when Part B becomes effective.

The period can run even if you:

• Keep employer group coverage
• Do not purchase a Medicare Supplement policy
• Do not begin using Medicare as your primary coverage
• Plan to retire later

The Medigap window ordinarily does not restart when the employer coverage eventually ends.

This is why the timing of Part B enrollment should be coordinated carefully when someone plans to continue working.

What if You Initially Choose Medicare Advantage?

Joining Medicare Advantage does not pause your Medicare Supplement Open Enrollment Period.

If your Part B coverage begins and you choose Medicare Advantage instead of Original Medicare with a Medicare Supplement, the six-month Medigap period can continue running in the background.

You cannot use a Medicare Supplement policy while enrolled in Medicare Advantage.

Some people who try Medicare Advantage for the first time may later qualify for a Medicare Advantage trial right. Depending on the circumstances, a trial right may allow someone to return to Original Medicare and purchase eligible Medicare Supplement coverage without medical underwriting.

However, trial rights have specific requirements and deadlines. Do not assume that leaving Medicare Advantage automatically guarantees acceptance into any Medicare Supplement policy.

The right to leave Medicare Advantage and the right to purchase Medicare Supplement coverage are related but separate issues.

Can You Change Medicare Supplement Plans During Open Enrollment?

Yes. If your six-month Medicare Supplement Open Enrollment Period is still active, you can generally apply for another Medicare Supplement policy without medical underwriting.

This can include changing:

• From one insurance company to another
• From Plan G to Plan N
• From Plan N to Plan G
• From another standardized plan to an available plan
• To a policy with a more competitive premium
• To a company offering a suitable household discount

The new company still needs to process the application and confirm the effective date.

Keep the existing policy active until the replacement is approved and you have reviewed the new coverage.

When replacing one Medicare Supplement policy with another, you receive a 30-day free-look period. You should expect to pay both premiums while both policies remain active during that review period.

Are All Medicare Supplement Plans Available During Open Enrollment?

An insurance company must offer every Medicare Supplement policy it sells for which you are eligible. However, not every person is eligible for every standardized plan letter.

People who first became eligible for Medicare on or after January 1, 2020, cannot purchase plans that cover the Medicare Part B deductible.

This generally means they cannot newly purchase:

• Medicare Supplement Plan C
• Medicare Supplement Plan F
• High-Deductible Plan F

People who became eligible for Medicare before January 1, 2020, may still be eligible to purchase Plan C or Plan F if an insurance company offers the plan.

Plan availability also varies by insurance company and state. Open Enrollment prevents health-based denial; it does not require every company to sell every standardized plan.

Does Open Enrollment Guarantee the Lowest Premium?

No. Open Enrollment protects you from being charged more because of your health, but it does not guarantee that every insurance company will charge the same premium.

Premiums may still vary based on legally permitted factors such as:

• Insurance company
• Standardized plan letter
• Age
• Geographic area
• Tobacco status
• Household eligibility
• Available discounts
• The company’s pricing method

The least expensive policy today is not automatically the best long-term choice.

It is also important to consider:

• The company’s rate history
• How discounts work
• Whether a discount decreases or ends
• Financial strength
• Customer service
• Administrative reliability
• The total annual premium

Open Enrollment gives you the opportunity to compare companies without your health limiting the decision.

What Happens After Medicare Supplement Open Enrollment Ends?

You can still apply for Medicare Supplement coverage after your six-month Open Enrollment Period ends.

However, unless you have a guaranteed-issue right or another protected enrollment opportunity, the insurance company may use medical underwriting.

Depending on the company and your health history, the application may be:

• Approved
• Delayed while additional information is reviewed
• Subject to further medical questions
• Declined

The company may review:

• Recent hospitalizations
• Current treatment
• Prescription medications
• Pending surgery
• Pending diagnostic testing
• Serious medical conditions
• Skilled-nursing or rehabilitation care
• Home healthcare
• Other company-specific factors

Underwriting requirements vary among companies. Approval from one company does not guarantee approval from another, and a denial from one company does not necessarily mean every company will decline you.

What Is the Difference Between Open Enrollment and Guaranteed Issue?

Medicare Supplement Open Enrollment and guaranteed-issue rights both provide protection from health-based denial, but they are not the same.

Medicare Supplement Open Enrollment:

• Lasts six months
• Is tied to your age and Part B enrollment
• Generally allows you to purchase any Medigap policy the company sells for which you are eligible
• Does not repeat every year

Guaranteed-issue rights:

• Result from specific coverage changes or protected events
• Have strict application deadlines
• May limit which standardized plans must be offered
• Require documentation proving the qualifying event

Situations that may create guaranteed-issue rights include certain losses of employer coverage, a Medicare Advantage plan leaving your area, moving outside a plan’s service area, or qualifying for a Medicare Advantage trial right.

A premium increase by itself does not generally create a federal guaranteed-issue right.

What About Pennsylvania Residents Under Age 65?

Pennsylvania requires Medicare Supplement insurance companies to offer Medigap coverage to Medicare beneficiaries under age 65 during their applicable Open Enrollment Period.

This can include people who qualify for Medicare because of:

• A disability
• End-stage renal disease

Plan availability and premiums for applicants under 65 may differ from those available to beneficiaries age 65 or older.

A person who qualifies for Medicare before 65 also receives another six-month Medigap Open Enrollment Period upon turning 65 while enrolled in Medicare Part B.

That new period can provide additional company choices and potentially more competitive premiums.

Does Each Spouse Have a Separate Open Enrollment Period?

Yes. Medicare Supplement policies cover one person.

Married couples do not share a Medicare Supplement policy or a single Open Enrollment Period. Each spouse has an individual six-month window based on that person’s age and Medicare Part B effective date.

One spouse may therefore be in Medicare Supplement Open Enrollment while the other is not.

Some insurance companies offer household discounts when both spouses or qualifying household members purchase coverage, but each person must submit a separate application.

What Should You Compare During Open Enrollment?

The six-month period gives you an important opportunity to choose coverage without medical underwriting.

Before selecting a policy, compare:

• Standardized plan benefits
• Monthly and annual premiums
• Plan G and Plan N differences
• Household discounts
• Pricing methods
• Company rate history
• Financial strength
• Customer service
• Application processing
• Any company-specific non-insurance extras

The standardized medical benefits of a particular plan letter are the same regardless of the insurance company.

For example, the core medical benefits of Plan G are standardized. The premium, discounts, service, and company history can differ.

Do not select a company based solely on a small introductory price difference.

What Are Common Medicare Supplement Open Enrollment Mistakes?

Common mistakes include:

• Confusing Medigap Open Enrollment with Medicare Annual Enrollment
• Assuming the six-month period returns every year
• Enrolling in Part B without realizing the Medigap window has started
• Delaying an application until the final days
• Assuming Medicare Advantage pauses the Medigap window
• Choosing a company based only on the lowest current premium
• Failing to compare Plan G and Plan N
• Ignoring household-discount rules
• Assuming health questions mean the company can deny you
• Cancelling existing coverage before replacement coverage is approved
• Failing to investigate a possible pre-existing-condition waiting period

Understanding the timing before Part B begins can prevent many of these problems.

How Can an Independent Medicare Broker Help?

An independent Medicare broker can help you use the six-month Open Enrollment Period effectively.

A broker can help you:

• Confirm when your Medigap Open Enrollment Period begins and ends
• Compare standardized plans
• Compare premiums from multiple insurance companies
• Review Plan G and Plan N
• Identify available household discounts
• Explain how each company prices its policies
• Review possible pre-existing-condition waiting periods
• Coordinate the policy’s effective date
• Avoid gaps or unnecessary overlapping coverage
• Understand what may happen after Open Enrollment ends

There is generally no additional fee to the consumer for using an independent Medicare broker.

The Bottom Line

Medicare Supplement Open Enrollment is your one-time six-month opportunity to purchase Medigap coverage with strong federal protections.

For someone age 65 or older, the period begins the first month the person is both at least 65 and enrolled in Medicare Part B.

During this period, an insurance company cannot deny an eligible policy, charge you more because of your health, or require you to qualify through medical underwriting.

The period does not repeat every year and is not the same as Medicare’s October 15 through December 7 Annual Enrollment Period.

Because your plan and company decisions can affect your future premiums and ability to change coverage, use this six-month window carefully.

Frequently Asked Questions

How long does Medicare Supplement Open Enrollment last?

It lasts six months, beginning the first month you are both at least 65 and enrolled in Medicare Part B.

Can I be denied during Medicare Supplement Open Enrollment?

An eligible applicant cannot be denied a Medicare Supplement policy because of health problems during the six-month Open Enrollment Period.

Does Medicare Supplement Open Enrollment happen every year?

No. It is generally a one-time six-month period and does not return every October.

Can a company charge me more because of my health during Open Enrollment?

No. A company cannot charge you more because of past or present health problems during your protected Medigap Open Enrollment Period.

Can a pre-existing condition have a waiting period?

Possibly. A company may delay coverage related to a pre-existing condition for up to six months in certain situations. Prior creditable coverage may reduce or eliminate that waiting period.

If I delay Medicare Part B will I lose my Medigap Open Enrollment Period?

If you properly delay Part B while covered through qualifying active-employment group coverage, your Medigap Open Enrollment Period generally begins when your Part B coverage later becomes effective.

Does Medicare Annual Enrollment let me purchase Medigap without underwriting?

No. The October 15 through December 7 Annual Enrollment Period does not create a new Medicare Supplement Open Enrollment Period.

Can I switch Medicare Supplement companies during my six-month period?

Yes. If your six-month Open Enrollment Period is still active, you can generally apply for another available Medicare Supplement policy without medical underwriting.

Do Pennsylvania residents under 65 receive Medigap Open Enrollment?

Yes. Pennsylvania requires Medicare Supplement companies to offer coverage to qualifying beneficiaries under 65 during their applicable Open Enrollment Period.

Does joining Medicare Advantage pause my Medigap Open Enrollment Period?

No. Your Medigap Open Enrollment Period can continue running after Part B begins even if you enroll in Medicare Advantage.

Related Medicare Topics

• Medicare Supplement Underwriting in Pennsylvania
• Can You Be Denied a Medicare Supplement Plan?
• Can I Switch Medicare Supplement Plans With Health Problems?
• When Can I Switch My Medicare Supplement Plan?
• Can I Switch Medicare Supplement Companies Without Losing Coverage?

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