Can You Have Medicare Part B Without Part A?

Yes, you can have Part B alone, but it is uncommon and comes with trade-offs

You can enroll in Medicare Part B without Part A, but most people do not because Part A (hospital insurance) is free at 65 if you or your spouse paid Medicare taxes for at least 10 years. Part B (medical insurance) costs a monthly premium — $164.90 in 2024, though the amount changes yearly — and covers doctor visits, outpatient care, and some preventive services.

The main reason to take Part B without Part A is if you are still working at 65 and have health coverage through your employer. In that case, you can delay Part A without penalty, but you may want Part B to cover services your employer plan does not. Another reason is if you are not yet 65 and become disabled or have end-stage renal disease — you can get Part B before Part A becomes available.

If you turn down Part B when you first become may be able to access and do not have a valid reason (called a may have access to event), you will pay a permanent 10 percent penalty on your Part B premium for each full year you went without it. This penalty stays with you for life, so the decision matters.

Key Takeaways

Part A is free for most people at 65 if they or a spouse paid Medicare taxes for 10 years; Part B costs a monthly premium and is optional if you have other coverage.
You can enroll in Part B alone if you are working and covered by an employer plan, or if you are under 65 with a disability or kidney disease.
Turning down Part B without a may have access to reason triggers a permanent 10 percent premium penalty for each year you delay.
Your initial enrollment window is seven months centered on the month you turn 65; missing it without a valid reason locks in the penalty.
If you have an employer plan, you must tell Medicare when you lose that coverage so you can enroll in Part B without penalty.

When Part B alone makes sense

The clearest case is still working at 65 with employer coverage. Your employer plan may cover things Part B does not — dental, vision, hearing — or may have lower out-of-pocket costs. You can stay on your employer plan and skip Medicare Part B entirely during those years. When you retire or lose the coverage, you have a window to enroll in Part B without the late penalty.

Another scenario is being under 65 and disabled. You become may be able to access for Medicare after receiving Social Security Disability Insurance (SSDI) for 24 months. At that point, you can enroll in Part B even though Part A is not yet available to you. This is rare but happens when someone on disability needs coverage for doctor visits or outpatient services that SSDI does not cover.

A third case is end-stage renal disease (ESRD). You can get Medicare at any age if you have ESRD and need dialysis or a transplant, and you can choose Part B without Part A if your situation calls for it — though most people with ESRD need both.

The penalty for turning down Part B

If you do not enroll in Part B during your initial enrollment period (seven months: three months before the month you turn 65, the month itself, and three months after), and you do not have a may have access to reason to delay, Medicare charges you a 10 percent premium penalty for each full year you went without it. This penalty is permanent — it does not go away once you finally enroll.

For example, if you turn 65 in January 2024 and skip Part B until January 2026 (two years), your Part B premium will be 20 percent higher than the standard rate for the rest of your life. In 2024, that standard premium is $164.90 per month; a 20 percent penalty adds $32.98 to every monthly bill forever.

The penalty does not explore if you have a may have access to event: employer coverage that counts as creditable coverage, COBRA, Medicaid, or certain other plans. You must tell Medicare about the may have access to event within 63 days of losing that coverage, or the penalty clock starts ticking.

How to enroll in Part B without Part A

Contact Social Security during your initial enrollment period or within 63 days of losing employer coverage. You can call 1-800-772-1213, visit your local Social Security office, or go online to ssa.gov. Tell them you want to enroll in Part B only.

You will need to show proof of your employer coverage (or other may have access to coverage) if you are using that as your reason to delay Part A. A letter from your employer's benefits department or a copy of your health plan documents usually works. Social Security will confirm your enrollment and tell you when your Part B coverage starts — usually the first of the month after you enroll.

If you are under 65 with a disability or ESRD, the process is the same: contact Social Security and request Part B enrollment. They will verify your condition and set your start date.

What Part B covers that Part A does not

Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health services. Part B covers doctor visits, lab tests, imaging, outpatient surgery, mental health services, and preventive care like screenings and vaccines. If you have Part B without Part A, you are covered for all doctor and outpatient services, but not for hospital stays.

This matters if you are still working and your employer plan covers hospital care. You can rely on that plan for inpatient services and use Part B for outpatient care. Once you retire and lose the employer plan, you will need to enroll in Part A to cover hospital stays, or buy a Medigap or Medicare Advantage plan that includes hospital coverage.

Enrolling in Part A later without penalty

If you have employer coverage at 65 and skip both Part A and Part B, you can enroll in Part A later without penalty — Part A has no late-enrollment penalty. However, Part B does, so you must be careful about the timing.

When you lose your employer coverage, you have a 63-day window to enroll in Part B without penalty. During this same window, you can also enroll in Part A if you have not already. Tell Social Security about the loss of coverage and request both parts. If you wait longer than 63 days, the Part B penalty applies, but Part A enrollment remains penalty-free.

Many people in this situation enroll in Part A right away (since it is free and has no penalty) and delay Part B until they retire, as long as they notify Social Security within 63 days of losing employer coverage.

Medicare Advantage and Medigap with Part B only

If you enroll in Part B without Part A, you can still buy a Medigap (supplemental insurance) plan to fill gaps in coverage. However, your options are limited. Some Medigap plans require you to have both Part A and Part B, while others will sell to you with Part B alone. You will need to contact insurers directly to find out which plans are available in your area.

You cannot enroll in Medicare Advantage (Part C) without Part A. Medicare Advantage plans require both Part A and Part B, so this route is closed to you if you have Part B only.

This is another reason why Part B without Part A is uncommon: it limits your insurance options. Most people find it simpler to enroll in both parts at 65 and choose a Medigap or Advantage plan from the full menu of options.

Frequently Asked Questions

What happens if I miss my enrollment window and have no employer coverage?

You can still enroll in Part B, but you will pay the 10 percent penalty for each full year you delayed. The penalty is permanent. You can enroll during the General Enrollment Period (January 1 to March 31 each year), and coverage starts July 1. There is no way to avoid the penalty once the window closes unless you had a may have access to event.

If I have Part B only, am I covered if I need emergency surgery?

Part B covers outpatient surgery at a hospital or surgical center. If you need inpatient surgery that requires an overnight hospital stay, Part A covers the hospital part, but you do not have Part A. Your employer plan (if you still have one) would cover it. Once you retire and lose employer coverage, you must enroll in Part A to cover inpatient hospital care.

Can I switch from Part B only to both parts later?

Yes. You can enroll in Part A at any time without penalty — there is no late-enrollment penalty for Part A. When you are ready, contact Social Security and request Part A enrollment. Your coverage will start the first of the month after you enroll. Part B is already active, so you will have both.

Does my employer have to tell me I can skip Medicare?

No. Your employer may not mention Medicare at all. It is your responsibility to understand your options. If you are 65 and still working, contact Social Security yourself to learn whether your employer coverage counts as creditable coverage and what your enrollment options are.

What if my employer plan ends but I do not notice for four months?

You have 63 days from the date your coverage ends to enroll in Part B without penalty. If you miss that window, the 10 percent penalty applies. Contact Social Security as soon as you realize the coverage is gone and ask whether they can backdate your enrollment based on the actual end date of your employer plan — some situations allow this, but it is not may provide.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.