You can cancel Medicare Part B, but the process depends on when you want it to stop and whether you have other coverage

Cancelling Medicare Part B (medical insurance) is not automatic — you must contact Medicare directly and request the cancellation in writing. Medicare will not cancel it just because you stop paying the premium. The timing matters: if you cancel during the wrong time of year, your coverage may not end when you expect, or you may face a penalty if you drop it without other insurance in place. Most people who cancel Part B do so because they have employer coverage or because they are moving out of the country.

The process takes about 30 days from the date Medicare receives your request. Your coverage will end on the last day of the month in which Medicare approves your cancellation, unless you specify a different date. If you are cancelling because you have other insurance, you will need to show proof of that coverage to avoid a late-enrollment penalty later.

Key Takeaways

  • You must submit a written request to Medicare to cancel Part B; calling alone will not end your coverage.
  • Your Part B coverage ends on the last day of the month Medicare approves your cancellation, unless you request a different date.
  • If you cancel Part B without other medical insurance, you will owe a penalty (surcharge) if you rejoin Medicare later.
  • You can cancel Part B while keeping Part A (hospital insurance) if you have other coverage for doctor visits and outpatient care.
  • Employer coverage or Veterans Affairs coverage counts as proof of other insurance and protects you from the penalty.

How to submit a cancellation request to Medicare

Contact Medicare by phone, mail, or in person at your local Social Security office. The phone number is 1-800-MEDICARE (1-800-633-4227). When you call, tell the representative you want to cancel Part B and ask them to send you a cancellation form. Do not assume the call alone cancels your coverage — you must follow up with the written request.

You can also mail a letter directly to your Medicare contractor. Find your contractor's address by calling 1-800-MEDICARE or visiting Medicare.gov. Your letter should include your name, Medicare number, date of birth, and a clear statement that you want to cancel Part B. Sign and date the letter. Keep a copy for your records.

If you go in person to a Social Security office, bring your Medicare card and a photo ID. The office can help you fill out the cancellation form on the spot. Ask for a receipt or confirmation number before you leave.

When your cancellation takes effect

Medicare processes cancellation requests and ends your Part B coverage on the last day of the month after Medicare approves your request. If you submit your request on January 15, and Medicare approves it on February 10, your coverage will end on February 28 (or 29 in a leap year). You cannot choose an earlier date unless you request it in writing when you submit your cancellation.

If you want your coverage to end on a specific date other than the last day of the month, state that date clearly in your cancellation request. Medicare will try to honor the date you choose, but the last day of a month is the standard. Plan ahead: if you have other coverage starting on a certain date, submit your cancellation request at least 60 days before that date to avoid a gap or overlap.

The late-enrollment penalty if you cancel without other coverage

If you cancel Part B and do not have other medical insurance (such as employer coverage, TRICARE, or Veterans Affairs), you will owe a penalty when you rejoin Medicare later. The penalty is 10 percent of the standard Part B premium for each full year you were without Part B coverage after your initial enrollment period ended. This penalty is permanent — it stays on your account for as long as you have Part B.

For example, if you cancel Part B in 2024 and rejoin in 2026 without having other coverage in between, you will owe a penalty equal to 20 percent of the standard premium (10 percent per year for two years). The penalty is added to your monthly premium and does not go away if you later get other coverage.

To avoid this penalty, you must have proof that you had other insurance during the time you were not enrolled in Part B. Employer health plans, COBRA continuation coverage, TRICARE, Veterans Affairs coverage, and some state programs all count. When you rejoin Part B, bring documentation of that coverage with you.

Cancelling Part B while keeping Part A

You can cancel Part B and keep Part A (hospital insurance) if you have other coverage for doctor visits and outpatient services. Part A covers hospital stays, skilled nursing facility care, and some home health services. Part B covers doctor visits, lab tests, imaging, and outpatient procedures. If you have employer coverage or another plan that covers outpatient care, you can drop Part B without losing hospital coverage.

When you request cancellation, specify that you want to cancel Part B only. Medicare will confirm this in writing. Your Part A will remain active, and you will continue to pay the Part A premium (if applicable) or have it deducted from your Social Security check. You will no longer pay the Part B premium once your cancellation is approved.

What to do before you cancel

Before you submit a cancellation request, confirm that your other insurance will cover you starting on the date your Part B ends. Call your employer's benefits department or your other insurance provider and ask them to confirm the coverage start date in writing. Do not rely on a verbal promise. If there is a gap between when Part B ends and when your other coverage begins, you will have no medical insurance during that time.

Review your current prescriptions and any ongoing treatments. Some doctors and pharmacies may not accept your new insurance, so contact them ahead of time to make sure they are in-network. If you are in the middle of a course of treatment, ask your doctor whether cancelling Part B will affect your care.

Keep your Medicare card even after you cancel Part B. You will still have Part A, and you may need to show your Medicare number to providers. Do not destroy the card.

Rejoining Part B after you cancel

If you cancel Part B and later want to rejoin, you can do so during the General Enrollment Period, which runs from January 1 to March 31 each year. Your coverage will start on July 1 of that year. You cannot rejoin outside this window unless you have a may have access to life event (such as loss of employer coverage) that triggers a Special Enrollment Period.

When you rejoin, bring proof of the other insurance you had while you were not enrolled in Part B. This proof protects you from the late-enrollment penalty. Acceptable proof includes a letter from your employer confirming the dates of coverage, a copy of your insurance card, or a benefits statement. Without this proof, Medicare will assume you went without coverage and will assess the penalty.

Frequently Asked Questions

Can I cancel Part B over the phone?

No. Calling Medicare starts the process, but you must submit a written cancellation request. The representative can mail you a form or tell you where to send a letter. The written request is what actually cancels your coverage.

What happens to my Part B premium if I cancel mid-month?

Your Part B coverage ends on the last day of the month Medicare approves your cancellation. You will owe the full premium for that month. Medicare does not prorate the premium for partial months.

Do I lose my Medicare number if I cancel Part B?

No. Your Medicare number stays the same. You keep it for Part A and for any future Part B enrollment. Your Medicare card remains valid as long as you have Part A.

Can my employer cancel my Part B for me?

No. Only you or your authorized representative can request cancellation. Your employer cannot submit the request on your behalf, but they can provide you with a letter confirming your coverage dates, which you will need to avoid the penalty.

What if I move out of the United States?

You can cancel Part B if you move permanently out of the country. You will need to notify Medicare and provide proof of your move (such as a lease or utility bill from your new address). Part A coverage also ends when you leave the country, so you will lose all Medicare coverage.