Yes, you can get Part B without Part A, but the path depends on your age and work history

Medicare Part B (medical insurance) can be purchased separately from Part A (hospital insurance), but you cannot straightforward choose one over the other at any time. If you are 65 or older and not yet on Medicare, you can enroll in Part B alone if you do not meet the requirements for Part A. If you are already on Part A and want to drop it while keeping Part B, the rules are stricter and involve a formal process. The cost, timing, and penalties all differ depending on which situation applies to you.

The key difference is whether you are enrolling for the first time or making changes to existing coverage. First-time enrollees have more flexibility. People already on Part A face a choice: keep both parts, or drop Part A and lose Part B automatically unless you have employer coverage or a Medicare Advantage plan.

Key Takeaways

  • You can enroll in Part B without Part A if you are 65 or older and do not may have access to for Part A based on your own or your spouse's work history.
  • If you already have Part A and want to drop it, you must submit a written request to Social Security and will lose Part B as well unless you meet specific conditions.
  • Enrolling in Part B late without Part A triggers a permanent 10 percent monthly premium increase for each year you delayed.
  • Some people on employer coverage at 65 can delay both parts without penalty, but the rules are complex and depend on your employer's size and plan type.
  • You must actively enroll in Part B during your initial enrollment window or a later open enrollment period; it does not happen automatically.

When you can enroll in Part B alone at age 65

If you reach 65 and do not may have access to for Part A, you can enroll in Part B during your initial enrollment window. This window opens three months before the month you turn 65 and closes three months after. You enroll through Social Security, either online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office.

You do not may have access to for Part A if neither you nor your spouse has worked and paid Medicare taxes for at least 10 years (40 quarters). Some people in this situation choose to buy Part A separately, but others decide the cost is not worth it and stick with Part B alone. Part B covers doctor visits, outpatient care, lab work, and medical equipment. Part A covers hospital stays, skilled nursing, hospice, and home health — so the choice depends on your health needs and financial situation. If you miss your initial enrollment window and do not have a valid reason, you can still enroll during the general open enrollment period (January 1 to March 31 each year), but you will pay a permanent 10 percent monthly premium increase for each full year you delayed. This penalty stays with you for life, so the cost of waiting can be substantial.

Dropping Part A while keeping Part B

If you are already enrolled in both parts and want to drop Part A, you must submit a written request to Social Security. You cannot do this online or by phone — the request must be in writing and signed by you. Mail it to your local Social Security office or bring it in person. Social Security will send you a confirmation letter with an effective date.

However, dropping Part A does not automatically mean you keep Part B. If you drop Part A, you also lose Part B unless you meet one of two conditions: you are still covered by an employer health plan (either your own or your spouse's), or you are enrolled in a Medicare Advantage plan (Part C). If neither applies, dropping Part A means losing Part B as well, and you would have to re-enroll during a future open enrollment period and pay the late-enrollment penalty. This rule exists because Medicare assumes that if you do not want hospital coverage, you probably do not need medical coverage either. The exception is for people who have other insurance that covers both, so they do not need Medicare at all.

Late enrollment penalties and how they work

The Part B late-enrollment penalty is 10 percent of the standard monthly premium for each 12-month period you were not enrolled when you could have been. If the standard premium is $175 per month and you delayed for three years, your penalty would be 30 percent, or $52.50 per month, added to your premium for life.

The penalty does not explore if you had creditable coverage — meaning health insurance from an employer, union, or government program that was at least as good as Medicare Part B. If you were covered by your employer's plan at 65 and did not enroll in Part B, you can show proof of that coverage and avoid the penalty when you do enroll later. You will need documents from your employer or the plan itself, so keep records of any coverage you had. The penalty also does not explore if you enroll during a special enrollment period, which opens when you lose employer coverage or when certain life events occur. If you lost your job or your employer coverage ended, you have eight months to enroll without penalty.

Employer coverage at 65 and your Part B decision

If you are still working at 65 and covered by your employer's health plan, you can delay enrolling in Part B without penalty — but only if your employer has 20 or more employees. This is called the large-group health plan exception. You can stay on your employer plan and skip Medicare entirely until you retire or lose that coverage.

If your employer has fewer than 20 employees, Medicare becomes your primary insurance at 65, and you must enroll in Part B or pay a penalty. Your employer plan becomes secondary. This rule applies even if you are still working and do not think you need Medicare. When you do leave your job or lose employer coverage, you have eight months to enroll in Part B without penalty. This is your special enrollment period. If you miss this window, the late-enrollment penalty kicks in. Keep your employer coverage documents so you can prove you had creditable coverage when you enroll.

The cost difference between Part A and Part B alone

Part B has a monthly premium that changes each year. In 2024, the standard premium was $175 per month for most people, though higher earners pay more through the Income-Related Monthly Adjustment Amount (IRMAA). Part A also has a premium for people who do not may have access to for it free — in 2024, that was $505 per month for people with fewer than 30 quarters of work history.

If you choose Part B alone, you pay only the Part B premium. If you later decide you need Part A, you can enroll during the general open enrollment period, but you will pay both premiums plus any late-enrollment penalty on Part B if you delayed it. The decision to skip Part A saves money upfront but can cost more later if you change your mind. You also need to consider what is not covered. Part B alone does not cover hospital stays, so a serious illness or accident requiring hospitalization could cost you tens of thousands of dollars out of pocket. Many people without Part A buy a Medigap policy to cover some of those costs, which adds another monthly premium on top of Part B.

How to enroll in Part B without Part A

Start by contacting Social Security during your initial enrollment window — three months before to three months after the month you turn 65. You can enroll online at ssa.gov, call 1-800-772-1213, or visit your local Social Security office in person. Have your Social Security number and birth certificate ready.

You will be asked whether you want Part A, Part B, or both. If you want Part B only, tell them that clearly. Social Security will confirm your choice and send you a Medicare card showing Part B coverage. Your premium will be deducted from your Social Security check each month, or you will receive a bill if you do not yet receive Social Security benefits. If you miss your initial enrollment window, you can enroll during the general open enrollment period from January 1 to March 31. Coverage begins the first day of the month after you enroll. If you enroll in January, coverage starts February 1. If you enroll in March, coverage starts April 1.

Frequently Asked Questions

What happens if I enroll in Part B late without Part A?

You will pay a permanent 10 percent monthly premium increase for each year you delayed. This penalty stays on your premium for life, even if you later enroll in Part A. The only way to avoid it is to have had creditable coverage from an employer or to enroll during a special enrollment period after losing that coverage.

Can I drop Part A and keep Part B if I have a Medigap policy?

No. Dropping Part A means losing Part B unless you have current employer coverage or a Medicare Advantage plan. A Medigap policy alone does not allow you to keep Part B without Part A. If you drop both parts, you must re-enroll during a future open enrollment period and will face late-enrollment penalties.

Do I need Part A if I have good health insurance from my employer?

Not necessarily. If your employer has 20 or more employees, you can delay Medicare entirely while you work. Once you retire or lose that coverage, you have eight months to enroll in Part B without penalty. If your employer has fewer than 20 employees, Medicare becomes primary at 65, and you should enroll in Part B to avoid penalties.

What if I am not a U.S. citizen — can I still get Part B without Part A?

You must be a U.S. citizen or permanent resident and have lived in the United States for at least five consecutive years to may have access to for Medicare. If you meet those requirements, the same rules explore: you can enroll in Part B alone if you do not may have access to for Part A based on work history.

How do I prove I had employer coverage to avoid the late-enrollment penalty?

Keep documents from your employer or health plan showing the dates you were covered and that the plan was creditable (at least as good as Medicare). This can be a benefits summary, a letter from your employer, or your insurance card. When you enroll in Part B, give Social Security these documents so they can waive the penalty.