When and how to sign up for Part B coverage

You enroll in Medicare Part B during your Initial Enrollment Period, which runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. If you miss this window, you can still enroll later, but you will pay a permanent penalty on your monthly premium unless you have a valid reason for the delay.

The three ways to enroll are online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online enrollment takes about 10 minutes. By phone, expect to answer questions about your citizenship, current coverage, and income. In person, bring your Social Security card, proof of citizenship (passport or birth certificate), and proof of residency (utility bill or lease).

Your Part B coverage starts on the first day of the month after you enroll, or on the first day of the month you turn 65 if you enroll during your Initial Enrollment Period. You will receive a Medicare card in the mail within two weeks of enrollment.

Key Takeaways

  • You have seven months to enroll in Part B without penalty: three months before you turn 65, the month you turn 65, and three months after.
  • You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or at your local Social Security office.
  • If you delay enrollment past your Initial Enrollment Period without a valid reason, you will pay a permanent 10 percent penalty added to your monthly premium for as long as you have Part B.
  • Your coverage begins on the first day of the month after you enroll, or the first of the month you turn 65 if you enroll during your Initial Enrollment Period.

What happens if you miss your enrollment window

If you do not enroll during your seven-month Initial Enrollment Period, you enter a General Enrollment Period that runs from January 1 to March 31 each year. You can enroll during any General Enrollment Period, and your coverage will start July 1 of that year. However, you will owe a late enrollment penalty.

The penalty is 10 percent of the standard Part B premium for each full 12 months you were may be able to access but not enrolled. If you were may be able to access for two years and did not enroll, your penalty is 20 percent. This penalty stays on your premium for as long as you have Part B, so delaying enrollment is costly. The only exceptions are if you were covered by a group health plan through current employment, or if you were living outside the United States and covered by the Veterans Health Administration.

Situations where you do not need to enroll right at 65

If you are still working and covered by your employer's health plan, you do not have to enroll in Part B at 65. You can delay without penalty as long as your employer plan covers at least 20 employees. When you leave that job or lose the coverage, you have eight months to enroll in Part B without owing a late penalty. This is called your Special Enrollment Period.

Similarly, if you are a federal employee or retiree covered by the Federal Employees Health Benefits Program (FEHB), you can delay Part B enrollment. Once you lose that coverage, you have eight months to enroll without penalty. The same rule applies if you are covered by TRICARE (military health coverage) or the Veterans Health Administration.

If you are not sure whether your current coverage qualifies you to delay, contact Medicare at 1-800-MEDICARE before your 65th birthday. They can tell you whether your plan allows you to delay without penalty.

What you need to know about Part B costs

Part B has a monthly premium that changes each year. In 2024, the standard premium is $164.90 per month, but higher-income beneficiaries pay more through an Income-Related Monthly Adjustment Amount (IRMAA). Your premium is deducted automatically from your Social Security check, or you receive a bill if you do not receive Social Security.

Part B also has an annual deductible (currently $240) that you pay before Medicare starts to cover services. After you meet the deductible, you typically pay 20 percent of the cost of doctor visits, lab tests, and other services that Medicare covers. There is no out-of-pocket maximum under Original Medicare Part B alone, which is why many people also purchase a Medigap policy or enroll in a Medicare Advantage plan.

How to check your enrollment status

Once you enroll, you can check your Part B status online by creating an account at Medicare.gov. Log in, select "My Medicare", and you will see your coverage details. You can also call 1-800-MEDICARE to confirm your enrollment status, or visit your local Social Security office.

Your Medicare card will show whether you have Part B coverage. If you enrolled online or by phone, your card arrives within two weeks. If you do not receive it by then, call 1-800-MEDICARE to request a replacement.

What to do after you enroll

After you enroll in Part B, you should choose a primary care doctor who accepts Medicare. Not all doctors do, so call ahead to confirm. You can search for doctors in your area at Medicare.gov under "Care Provider Search".

You should also decide whether you want Original Medicare (Part A and Part B) alone, or whether you want to add prescription drug coverage (Part D) and supplemental coverage. If you do not enroll in Part D when you first become may be able to access, you will owe a penalty if you join later, unless you have had other creditable prescription drug coverage. The important date to avoid this penalty is 63 days after you lose other coverage or after your Initial Enrollment Period ends, whichever is later.

Frequently Asked Questions

Can I enroll in Part B after I turn 65 if I missed my Initial Enrollment Period?

Yes. You can enroll during the General Enrollment Period (January 1 to March 31 each year), and your coverage starts July 1. However, you will owe a late enrollment penalty of 10 percent of the standard premium for each full 12 months you were may be able to access but not enrolled. This penalty is permanent.

What if I am still working at 65 and have health insurance through my job?

You do not have to enroll in Part B at 65 if your employer plan covers at least 20 employees. When you leave that job or lose the coverage, you have eight months to enroll in Part B without owing a late penalty. Contact Medicare before your 65th birthday to confirm your plan qualifies.

How much does Part B cost per month?

The standard Part B premium changes each year. In 2024, it is $164.90 per month, but higher-income beneficiaries pay more. Your premium is deducted from your Social Security check, or you receive a bill if you do not receive Social Security. You also pay an annual deductible and 20 percent of covered services after that.

What documents do I need to bring if I enroll in person at Social Security?

Bring your Social Security card, proof of citizenship (passport or birth certificate), and proof of residency (utility bill, lease, or mortgage statement). If you are enrolling on behalf of someone else, bring their documents plus a power of attorney or guardianship papers.

When does my Part B coverage start after I enroll?

If you enroll during your Initial Enrollment Period (the seven months around your 65th birthday), coverage starts the first of the month you turn 65 or the first of the month after you enroll, whichever is later. If you enroll during a General Enrollment Period, coverage starts July 1 of that year.