Part B is not automatic — you have to choose it, and the choice has real consequences

Part B Medicare covers doctor visits, outpatient care, and preventive services. It is not included in Part A (hospital insurance). You must actively choose to take it during your enrollment window, or you may face a permanent penalty on your premiums if you sign up later.

Most people do take Part B when they turn 65, but you can decline it if you have other coverage — usually through an employer or union. The catch: if you drop it and later rejoin, Medicare adds a surcharge to your monthly premium for as long as you have Part B. That surcharge does not go away.

Key Takeaways

  • Part B is optional at age 65, but you must actively enroll during your Initial Enrollment Period or face a permanent premium penalty.
  • You can turn down Part B only if you have creditable coverage through an employer, union, or TRICARE — and you must document this when you later sign up.
  • The late enrollment penalty is 10 percent of the standard Part B premium for each full year you delayed, added to your premium forever.
  • If you work past 65 and have employer coverage, you have eight months after you leave that job to sign up for Part B without penalty.
  • Dropping Part B after you have enrolled is possible but unusual, and you can only do it during the annual Open Enrollment Period in the fall.

When you can legally skip Part B

You can turn down Part B at 65 only if you have creditable coverage — insurance that is at least as good as Medicare Part B. This usually means coverage through your own job, your spouse's job, or a union. TRICARE (military retiree coverage) also counts. You cannot skip Part B just because you do not see a doctor often or think you are healthy.

When you do have creditable coverage, you must tell Social Security or Medicare that you are declining Part B. Keep a record of this decision. You will need proof of that coverage — usually a letter from your employer's benefits office or a copy of your insurance card — when you eventually sign up for Part B. Medicare will ask for it.

If you are still working at 65 and covered by your employer's health plan, you have until eight months after you leave that job to sign up for Part B without paying a penalty. This is called the Special Enrollment Period. The clock starts the month after your coverage ends, not the month you retire.

What happens if you delay Part B without creditable coverage

If you turn 65 and do not take Part B, and you do not have creditable coverage to fall back on, Medicare will charge you a penalty every month for the rest of your life. The penalty is 10 percent of the standard Part B premium for each full year you did not have Part B. If you wait three years, your penalty is 30 percent of the standard premium, added to your bill every month forever.

This penalty does not expire. It stays on your account even if you move to a different state, switch plans, or live to 95. The only exception is if you can prove you had creditable coverage during the time you were not enrolled — and you must provide that proof to Medicare in writing.

The standard Part B premium changes each year. In 2024, the standard premium was $164.90 per month, but this amount varies based on your income. A 10 percent penalty would add roughly $16.49 to your monthly bill. Over ten years, that adds up to nearly $2,000 in extra costs.

How to decline Part B if you are still working

When you turn 65, Social Security will contact you about Medicare. You will receive a notice in the mail asking whether you want to enroll in Part B. If you are still working and covered by your employer's plan, you can say no on that form. Write down the date you received the notice and keep a copy of your response.

You should also contact your employer's benefits office and ask them to send you a letter stating that you have creditable coverage through their health plan. This letter is your proof that you had good reason to decline Part B. Store it with your Medicare paperwork.

When you leave your job, you will have eight months to sign up for Part B without penalty. Contact Social Security or Medicare during that window. Bring the letter from your employer proving you had coverage, and bring your final pay stub or a letter from your employer confirming your last day of work. This documentation protects you from the late enrollment penalty.

Dropping Part B after you have enrolled

Once you are enrolled in Part B, you cannot straightforward cancel it whenever you want. You can drop Part B only during the Annual Enrollment Period, which runs from October 15 to December 7 each year. Changes take effect the following January 1.

You might drop Part B if you move to a country outside the United States, or if you enroll in a Medicare Advantage plan that includes Part B and you want to switch to Original Medicare without Part B. These situations are rare. Most people who have Part B keep it.

If you drop Part B and later want it back, the same late enrollment penalty rules explore. You will pay 10 percent extra for each year you were without it. This is why dropping Part B is usually not a good idea unless you are moving abroad or have a very specific reason.

Understanding the enrollment windows and important date

Your Initial Enrollment Period is the seven-month window centered on your 65th birthday: three months before, the month you turn 65, and three months after. If you miss this window and do not have creditable coverage, you will face a penalty when you eventually enroll.

If you are still working at 65 and covered by an employer plan, your Special Enrollment Period begins the month after your coverage ends and lasts eight months. This is your penalty-free window to sign up for Part B. Do not wait until the following year.

The Annual Enrollment Period (October 15 to December 7) is when you can make changes to your Medicare coverage if you are already enrolled. You can switch between Original Medicare and Medicare Advantage plans, or drop Part B if you have a may have access to reason. Changes made during this period take effect January 1.

What to ask your doctor and employer

If you are still working and thinking about declining Part B, ask your employer's benefits office: "Is this plan considered creditable coverage under Medicare rules?" and "Can you send me a written statement of that coverage?" Get the answer in writing and keep it.

Ask your doctor: "If I do not have Part B, will you still see me?" Some doctors do not accept patients without Medicare Part B, even if they have other insurance. Knowing this before you decline Part B can save you from losing your doctor.

If you are unsure whether your coverage is creditable, call Medicare at 1-800-MEDICARE (1-800-633-4227) and describe your employer plan. They can tell you whether it counts as creditable coverage for Medicare purposes.

When to contact Medicare

Contact Medicare if you are within three months of your 65th birthday and have not yet received a notice about Part B enrollment. Call 1-800-MEDICARE or visit your local Social Security office.

If you are still working and covered by an employer plan, contact Medicare within one month after your coverage ends to sign up for Part B without penalty. Do not wait. The eight-month window is your protection, but the sooner you enroll after coverage ends, the sooner your Part B coverage begins.

If you enrolled in Part B and now want to drop it, contact Medicare during the Annual Enrollment Period (October 15 to December 7) to request a disenrollment form. You will need to explain your reason for dropping it.

Frequently Asked Questions

Can I have Medicare Part A without Part B?

Yes. Part A (hospital insurance) and Part B (doctor and outpatient care) are separate. You can have Part A alone if you have creditable coverage for doctor visits through an employer or other source. However, most people eventually take both because Part B covers preventive care and doctor visits that Part A does not.

What if I missed my Initial Enrollment Period and did not know about the penalty?

Contact Medicare and explain your situation. If you can show that Social Security or Medicare did not properly inform you, or if you had creditable coverage during the time you were not enrolled, you may be able to avoid or reduce the penalty. You will need documentation of that coverage. Call 1-800-MEDICARE to discuss your specific case.

Does the Part B penalty ever go away?

No. The late enrollment penalty is permanent. It stays on your account for as long as you have Part B. The only way to avoid it is to enroll during your Initial Enrollment Period or within eight months of losing creditable coverage through an employer.

If I work past 65, when should I sign up for Part B?

You have eight months after your employer coverage ends to sign up without penalty. That eight-month window is your Special Enrollment Period. Sign up as soon as possible after your coverage ends so your Part B coverage begins quickly. Do not wait until the end of the eight months.

Can I drop Part B and go back to just Part A?

Yes, but only during the Annual Enrollment Period (October 15 to December 7). You will need a may have access to reason, such as moving outside the United States. If you drop Part B and later want it back, you will pay the late enrollment penalty. This is usually not recommended unless you have a specific reason.