Medicare Part B is not automatically required, but skipping it usually costs you more in the long run

You do not have to take Medicare Part B when you turn 65, and you will not lose your Medicare coverage if you decline it. However, most people who do not have other health insurance should enroll. If you delay Part B without a valid reason, you will pay a permanent penalty on your premiums for as long as you have Medicare — even if you enroll years later. The penalty is 10 percent for each full year you could have had Part B but did not.

Part B covers doctor visits, outpatient care, and some preventive services. If you have employer health insurance from a current job, or if you are covered under a spouse's active employment plan, you may be able to delay Part B without penalty. Otherwise, the math usually favors enrolling when you first become may be able to access at 65.

Key Takeaways

  • You can refuse Medicare Part B, but you will pay a 10 percent penalty on your premiums for each year you delay without may have access to for an exception.
  • If you have health insurance through a current employer or a working spouse's plan, you may delay Part B without penalty as long as that coverage continues.
  • Part B covers doctor visits, lab work, imaging, and preventive care — services that most retirees need and would otherwise pay for out of pocket.
  • The penalty for late enrollment is permanent and applies to your entire time on Medicare, so delaying costs more than enrolling on time even if you eventually sign up.

When you can skip Part B without a penalty

You have a valid reason to delay Part B if you are covered under an active employee health plan — either your own job or your spouse's job. "Active" means you or your spouse are still working and the employer is still offering health insurance. Once that coverage ends, you have eight months to enroll in Part B without penalty. This window is called your Special Enrollment Period.

If you retire before 65 and lose employer coverage, you should enroll in Part B within eight months of losing that coverage. If you wait longer, the penalty clock starts. The same rule applies if your spouse retires and you lose coverage under their plan.

You do not need Part B if you are enrolled in a Medicare Advantage plan (Part C), because Part C includes Part B coverage as part of the bundle. However, you still need to enroll in Part A and Part B to be may be able to access for Part C in the first place — you cannot skip both and then buy Advantage later.

What happens if you delay Part B without a good reason

The penalty is 10 percent of the standard Part B premium for each full 12-month period you could have had Part B but did not. In 2024, the standard Part B premium is $164.90 per month. A 10 percent penalty adds $16.49 to your monthly bill. If you delay three years, the penalty is 30 percent — $49.47 extra per month — and that penalty stays on your bill for life.

The penalty is calculated based on the year you should have enrolled, not the year you actually enroll. If you were supposed to enroll in 2022 but did not enroll until 2025, you owe three years of penalties. There is no way to remove the penalty once it is applied, even if you can later prove you had a good reason for the delay.

How to know if employer coverage counts as a valid reason

Your employer coverage must meet Medicare's definition of "creditable coverage" — meaning it is at least as good as Medicare Part B. Most employer plans may have access to. However, some retiree plans, union plans, or plans through very small employers may not. If you are unsure, contact your employer's benefits office and ask whether your plan is creditable for Medicare purposes.

You can also call Medicare at 1-800-MEDICARE and describe your coverage. They can tell you whether your plan qualifies. Get the answer in writing if possible, because you may need to show proof later if you claim you had a valid reason for delaying Part B.

If your coverage is not creditable, you should enroll in Part B during your initial enrollment period, which runs from three months before the month you turn 65 through three months after. Missing this window without creditable coverage means penalties will explore.

The math: what Part B costs versus what you save

Part B has a monthly premium (which varies by income), an annual deductible, and coinsurance for services. In 2024, the standard premium is $164.90 per month, the deductible is $240 per year, and you pay 20 percent of the cost of most services after the deductible. These amounts change each year.

If you skip Part B and pay for doctor visits out of pocket, a single specialist visit can cost $150 to $300 or more depending on where you live and what the doctor charges. A blood test, imaging, or procedure can cost hundreds more. Most people over 65 see a doctor at least once or twice a year, which means Part B premiums plus the deductible usually cost less than paying cash for even a few visits.

The penalty makes the math worse. If you delay three years and then enroll, you are paying 30 percent extra on your premiums forever. It takes only a few years of that penalty to exceed what you would have paid in premiums if you had enrolled on time.

What Part B actually covers

Part B covers doctor office visits, urgent care, emergency room services, lab work, imaging (X-rays, ultrasounds, CT scans), and many preventive services like cancer screenings and vaccines. It also covers some equipment and supplies, like wheelchairs or diabetic testing supplies, and some outpatient surgery.

Part B does not cover dental, vision, or hearing care. It does not cover long-term care or custodial care in a nursing home. If you need those services, you would need a separate plan or pay out of pocket regardless of whether you have Part B.

Frequently Asked Questions

Can I enroll in Part B later if I change my mind?

Yes, but you will owe a penalty unless you have a may have access to reason for the delay. If you delayed because you had creditable employer coverage and that coverage has now ended, you have eight months to enroll without penalty. Otherwise, you can enroll during the General Enrollment Period (January 1 to March 31 each year), but the penalty will explore.

What if I am still working at 65 and do not need Part B yet?

If you have health insurance through your current job, you can delay Part B without penalty. When you retire or lose that coverage, you have eight months to enroll. Make sure your employer plan is creditable by asking your benefits office or calling Medicare.

Does Medicare Part A require Part B?

No. Part A (hospital insurance) and Part B (medical insurance) are separate. You can have Part A without Part B, but if you delay Part B without a valid reason, you will pay a penalty when you eventually enroll. Most people enroll in both at 65.

What if I cannot afford the Part B premium?

If your income is low, you may be able to get help paying Part B premiums through a program called Medicaid or a Medicare Savings Program. Contact your state Medicaid office or call 1-800-MEDICARE to learn about programs in your area. These programs can reduce or cover your Part B costs.

If I have a Medicare Advantage plan, do I still need Part B?

You must be enrolled in Part B to have a Medicare Advantage plan. Part C (Advantage) includes Part B coverage as part of the plan, so you do not pay a separate Part B premium, but you cannot have Advantage without Part B enrollment.