Yes, you can have Part B alone, but it is uncommon and usually costs more

You can enroll in Medicare Part B without Part A, but Medicare will not let you do it automatically. You have to actively choose Part B during your initial enrollment window or during a special enrollment period, and you will pay a higher premium because you are not also taking Part A. Most people who do this are still working past age 65 and have employer coverage, or they delayed Part A because they were not yet receiving Social Security.

The main reason people choose Part B alone is that they do not yet meet the requirements for Part A. Part A covers hospital stays, skilled nursing care, and hospice. Part B covers doctor visits, outpatient care, and preventive services. You can want one without the other, but the rules about when you can enroll are strict, and missing your window can lock you into a higher premium for life.

Key Takeaways

  • Part B without Part A is possible only if you actively enroll during your initial enrollment window or a may have access to life event, not through automatic enrollment.
  • You will pay a higher Part B premium if you do not also take Part A, because Medicare assumes you are choosing to delay Part A and penalizes the choice.
  • The most common reason to take Part B alone is that you are still working and covered by an employer plan, which delays your Part A may be able to access.
  • If you miss your enrollment window, you cannot enroll in Part B alone until the next general enrollment period, which runs January through March each year.
  • Delaying Part A while enrolled in Part B does not trigger a penalty on Part A itself, but you will pay more for Part B every month you are enrolled without Part A.

Who typically enrolls in Part B without Part A

The most common scenario is a person age 65 or older who is still working and covered by their employer's health plan. If your employer has 20 or more employees, your employer plan is primary, and Medicare is secondary. In this case, you might enroll in Part B to have it as backup coverage, but you do not need Part A yet because your employer plan covers hospital stays.

Another group is people who delayed Part A because they were not yet receiving Social Security benefits. If you are not yet taking Social Security at 65, you do not automatically enroll in Medicare Part A. You can choose to enroll in Part B only and keep working, then add Part A later when you turn 66, 67, or whenever you decide to claim benefits.

A third group is people who have other health coverage—such as TRICARE (military coverage), Veterans Affairs benefits, or a spouse's employer plan—and do not need hospital coverage yet. They enroll in Part B for doctor and outpatient coverage while keeping their primary insurance for hospital care.

How the premium penalty works when you skip Part A

If you enroll in Part B without Part A, Medicare charges you a higher Part B premium for every month you are enrolled in Part B but not Part A. This is called the Part B premium surcharge. The surcharge is 10 percent of the standard Part B premium for each full year you were may be able to access for Part A but did not enroll. If you were may be able to access for two years and did not enroll, you pay 20 percent more. This surcharge stays with you for as long as you have Part B.

The penalty applies only to Part B. Part A itself does not have a late enrollment penalty if you enroll within three years of when you first became may be able to access. However, if you wait more than three years to enroll in Part A, you will pay a 10 percent surcharge on your Part A premium for twice the number of years you delayed. The two penalties are separate and stack on top of each other if you delay both parts.

To avoid the Part B surcharge, you need to enroll in Part A before or at the same time you enroll in Part B. If you are still working and covered by an employer plan, you have a special enrollment period that lasts eight months after your employment or coverage ends. During that window, you can enroll in Part A without triggering the Part B surcharge, even if you are already enrolled in Part B.

Your enrollment window and what happens if you miss it

Your initial enrollment window is seven months long: three months before the month you turn 65, the month you turn 65, and three months after. If you turn 65 in June, your window runs from March through September. During this window, you can enroll in Part B alone without penalty, as long as you do not have other may have access to coverage.

If you miss your initial window, you cannot enroll in Part B until the next general enrollment period, which runs January 1 through March 31 each year. When you enroll during general enrollment, you will pay a permanent 10 percent surcharge on your Part B premium for each full year you were may be able to access but not enrolled. This surcharge is permanent—it does not go away when you turn 66 or 67.

The exception is if you have may have access to coverage that delays your enrollment. If you are still working and covered by an employer plan with 20 or more employees, or if you have TRICARE or VA coverage, you have a special enrollment period of eight months after that coverage ends. During that window, you can enroll in Part B without the late enrollment penalty.

How to enroll in Part B without Part A

To enroll in Part B alone, you must contact Social Security, not Medicare directly. You can call Social Security at 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 and that you are not enrolling in Part A at this time. They will ask why—whether you are still working, have other coverage, or another reason—to confirm you are may be able to access to delay Part A.

Social Security will give you a form to sign stating that you understand you are choosing to enroll in Part B without Part A. Keep a copy of this form. It protects you if Medicare later tries to charge you a penalty, because it documents that you made an active choice rather than missing a important date.

You will receive your Medicare card in the mail within two to three weeks. Your card will show Part B coverage only. When you are ready to add Part A—either because you stopped working, your employer coverage ended, or you decided to claim Social Security—you can enroll in Part A during a special enrollment period or during the next general enrollment period.

Adding Part A later without triggering a penalty

If you enrolled in Part B alone while still working, you have eight months after your employment or employer coverage ends to enroll in Part A without paying a late enrollment penalty. This eight-month window is your special enrollment period. You do not need to wait for the general enrollment period in January.

To add Part A, contact Social Security again and tell them your employment or coverage has ended. Bring documentation: a letter from your employer stating your last day of work, a notice from your employer plan showing coverage ended, or a notice from your health plan. Social Security will enroll you in Part A, and your coverage will start the first day of the month after you enroll or the first day of the month your employment ended, whichever is later.

If you miss the eight-month window, you can still enroll in Part A during the next general enrollment period (January through March), but you will pay a 10 percent surcharge on your Part A premium for twice the number of years you delayed. For example, if you delayed Part A for two years, you pay 20 percent more for Part A for life.

What Part B covers when you do not have Part A

Part B covers doctor visits, outpatient surgery, emergency room visits, diagnostic tests, and preventive care—the same services it covers whether or not you have Part A. The difference is that Part B does not cover hospital inpatient stays. If you are admitted to the hospital and do not have Part A, you will have to pay the full cost out of pocket, unless you have other coverage (employer plan, TRICARE, VA, or a private insurance policy) that covers hospital care.

Part B also does not cover skilled nursing facility care, home health care, or hospice—all of which are Part A services. If you need any of these services and do not have Part A, you will pay the full cost unless you have other insurance. This is why Part B alone is usually only a temporary choice for people who know they will add Part A within a few months or years.

You are still responsible for Part B cost-sharing: the annual deductible, coinsurance, and copayments. In 2024, the Part B deductible is $240 per year. After you meet the deductible, you typically pay 20 percent coinsurance for most services. If you cannot afford these costs, you may be able to get help from a Medicaid program in your state, even if you do not have Part A.

Frequently Asked Questions

Can I enroll in Part B without Part A if I am still working?

Yes, if your employer has 20 or more employees and you are covered by their health plan. Your employer plan is primary, so you can enroll in Part B as secondary coverage. You have a special enrollment period of eight months after your employment or coverage ends to add Part A without penalty.

What if I enrolled in Part B alone and now want to add Part A?

Contact Social Security and tell them you want to enroll in Part A. If your employer coverage ended recently, you have eight months to enroll without a late penalty. If more than eight months have passed, you can enroll during the next general enrollment period (January through March), but you will pay a surcharge on your Part A premium.

Will I pay more for Part B if I do not have Part A?

Yes. You will pay a 10 percent surcharge on your Part B premium for each full year you were may be able to access for Part A but did not enroll. This surcharge is permanent and does not go away if you add Part A later. The only way to avoid it is to enroll in Part A before or at the same time you enroll in Part B.

What happens if I need hospital care and I only have Part B?

You will have to pay the full cost of the hospital stay out of pocket, unless you have other insurance (such as an employer plan or TRICARE) that covers hospital care. This is why Part B alone is usually only temporary for people who plan to add Part A soon.

Can I enroll in Part B alone during the general enrollment period?

Yes, but you will pay a permanent 10 percent surcharge on your Part B premium for each full year you were may be able to access but not enrolled. It is better to enroll during your initial enrollment window (seven months around your 65th birthday) to avoid the surcharge.