When and how to enroll in Part A without Part B

You can sign up for Medicare Part A (hospital insurance) without enrolling in Part B (medical insurance) if you meet certain conditions. The most common reason is that you or your spouse still work and have employer health coverage. Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services — but not doctor visits or outpatient care, which Part B covers.

The enrollment process depends on your age and work status. If you are 65 or older and not yet receiving Social Security, you must contact Social Security directly to sign up for Part A only. If you are already receiving Social Security benefits, Medicare Part A is usually automatic at 65, but you can decline Part B and keep Part A. The key is understanding which route applies to your situation before your Initial Enrollment Period ends, because missing the important date can mean waiting months or years to enroll.

Key Takeaways

  • You can enroll in Part A only if you have employer coverage through your own job or your spouse's job, or if you straightforward do not want Part B.
  • If you are not yet receiving Social Security at 65, you must contact Social Security directly — Medicare will not automatically enroll you in Part A.
  • Your Initial Enrollment Period is the three months before, the month of, and the three months after your 65th birthday; enrolling during this window avoids late penalties.
  • You can enroll by phone with Social Security, by mail using Form CMS-40B, or online through Medicare.gov if you already have a Social Security account.
  • If you miss your Initial Enrollment Period and do not have may have access to coverage, you may face a permanent penalty on Part A premiums when you eventually enroll.

Who can enroll in Part A only

You are may be able to access to enroll in Part A only if you are 65 or older and a U.S. citizen or permanent resident who has lived in the country for at least five years. You do not need to have worked or paid Medicare taxes yourself — if your spouse worked and paid taxes, you can enroll on their record.

The most common reason to choose Part A only is that you have health coverage through your current job or your spouse's current job. This is called group health plan coverage. As long as you have this coverage, you can delay Part B without penalty. Part A is still worth enrolling in because it covers hospital care that your employer plan may not fully cover, and it does not cost you anything if you or your spouse has worked and paid Medicare taxes for at least 10 years (40 quarters).

You can also enroll in Part A only if you straightforward do not want Part B. There is no requirement to take both parts together, though most people do.

Your Initial Enrollment Period and why it matters

Your Initial Enrollment Period is a seven-month window: the three months before you turn 65, the month you turn 65, and the three months after. During this window, you can enroll in Part A without any penalty, regardless of whether you have other coverage.

If you miss this window and do not have group health plan coverage, you face a permanent 10 percent increase to your Part A premium for twice the number of years you delayed enrollment. For example, if you delay two years, you pay 20 percent more for life. This penalty applies only if you do not have may have access to coverage, so if you are still working with employer insurance, you are protected — but you must still enroll in Part A during your Initial Enrollment Period or during a Special Enrollment Period after your coverage ends.

If you are already receiving Social Security benefits when you turn 65, Medicare Part A is usually automatic. You will receive a Medicare card in the mail about three months before your 65th birthday. You can decline Part B on that card and keep Part A only.

How to enroll by phone with Social Security

The fastest way to enroll in Part A only is to call Social Security at 1-800-772-1213 (TTY 1-800-325-0778). Have your Social Security number, date of birth, and citizenship or immigration status ready. Tell the representative that you want to enroll in Part A only and that you do not want Part B. If you have employer coverage, mention that — it protects you from Part B penalties if you delay it.

Social Security will confirm your may be able to access, take your enrollment information, and tell you when your coverage begins. Coverage usually starts on the first day of the month in which you enroll, or the first day of the following month if you call after the 10th. Ask the representative for a confirmation number and write it down.

You can call Social Security Monday through Friday, 7 a.m. to 7 p.m. your local time. Wait times are shortest early in the morning and late in the week.

How to enroll by mail using Form CMS-40B

If you prefer to enroll by mail, request Form CMS-40B (process for Enrollment in Part A) from Social Security by calling 1-800-772-1213, or read it from the Social Security website. Fill out the form completely, including your name, Social Security number, date of birth, and citizenship status.

On the form, you will see a section asking whether you want Part B. Check "No" if you want Part A only. Sign and date the form, then mail it to your local Social Security office. You can find the address on the Social Security website or by calling the number above. Keep a copy for your records.

Processing by mail takes longer than by phone — usually two to four weeks. If you are near your Initial Enrollment Period important date, phone enrollment is safer because you get when ready confirmation.

How to enroll online through Medicare.gov

If you have a Social Security account, you can enroll in Part A through Medicare.gov. Go to the Medicare homepage, sign in with your Social Security username and password, and look for the enrollment option. You will answer questions about your age, citizenship, and whether you want Part A, Part B, or both.

Online enrollment is available 24 hours a day and gives you when ready confirmation. However, not all situations can be handled online — if you are self-employed, have a complex work history, or are enrolling on a spouse's record, you may need to call Social Security instead.

After you enroll online, you will receive a confirmation email. Your Medicare card will arrive in the mail within two to three weeks.

What happens after you enroll

Once you enroll in Part A, your coverage begins on the first day of the month in which you enroll, or the first day of the following month if you enroll after the 10th. You will receive a Medicare card in the mail showing that you have Part A coverage. The card will not show Part B because you declined it.

You do not pay a monthly premium for Part A if you or your spouse worked and paid Medicare taxes for at least 10 years. If you have not worked that long, you may pay a premium — the amount varies based on how many quarters of work history you have. Social Security will tell you the premium amount when you enroll.

Part A has a deductible (the amount you pay before coverage kicks in) and coinsurance (your share of costs after the deductible). For 2024, the Part A deductible for a hospital stay is $1,676 per benefit period. These amounts change each year. You will owe these costs when you use hospital services, so it is wise to understand them before you need care.

If you have employer coverage and want to delay Part B

If you enroll in Part A only because you have employer health coverage, you can delay Part B without penalty as long as you stay covered by that plan. This is called creditable coverage. When your employer coverage ends — because you retire, leave the job, or the company stops offering it — you have a Special Enrollment Period of eight months to enroll in Part B without penalty.

To protect yourself, keep records of your employer coverage: your health plan name, the dates you were covered, and any letters from your employer confirming that the coverage was creditable. When your coverage ends, contact Social Security or Medicare within the eight-month window to enroll in Part B. If you miss this window, you will pay a permanent penalty on Part B premiums.

Frequently Asked Questions

Can I enroll in Part A only if I am still working?

Yes. If you are 65 or older and still working with employer health coverage, you can enroll in Part A only. Your employer coverage protects you from Part B penalties if you delay it. When your job ends or your coverage stops, you have eight months to enroll in Part B without penalty.

What if I miss my Initial Enrollment Period?

If you miss your Initial Enrollment Period and do not have employer coverage, you may face a permanent 10 percent increase to your Part A premium. However, if you have group health plan coverage, you can enroll in a Special Enrollment Period within eight months of losing that coverage without penalty. Contact Social Security as soon as your coverage ends.

Do I have to pay a premium for Part A?

Most people do not pay a monthly premium for Part A if they or their spouse worked and paid Medicare taxes for at least 10 years. If you have not worked that long, you may pay a premium based on your work history. Social Security will tell you the exact amount when you enroll.

Can I change my mind and add Part B later?

Yes. You can enroll in Part B at any time after you enroll in Part A. However, if you enroll outside your Initial Enrollment Period and do not have may have access to coverage, you will pay a permanent penalty on Part B premiums. Contact Social Security or Medicare.gov to add Part B.

What is the difference between Part A and Part B?

Part A covers hospital stays, skilled nursing facilities, hospice, and some home health services. Part B covers doctor visits, outpatient care, lab tests, and medical equipment. You can have Part A only, but most people eventually need both.