When and how to enroll in Medicare Part A and Part B

You can sign up for Medicare Part A and Part B during your Initial Enrollment Period, which runs for seven months. It starts three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, your enrollment period runs from March through September.

Most people sign up online through Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. You can also contact Social Security directly at 1-800-772-1213. The process takes about 15 minutes online or on the phone.

If you miss your Initial Enrollment Period, you can still sign up during the General Enrollment Period, which runs January 1 through March 31 each year. However, you may pay a permanent penalty on your Part B premium if you enroll late without a valid reason for the delay.

Key Takeaways

  • Your Initial Enrollment Period is seven months long, starting three months before you turn 65 and ending three months after.
  • You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at a Social Security office.
  • Part A (hospital insurance) is usually free if you or your spouse paid Medicare taxes for at least 10 years.
  • Part B (medical insurance) costs a monthly premium that changes each year, and you pay it through automatic deduction from your Social Security check or bank account.
  • Missing your enrollment important date can result in a permanent increase to your Part B premium unless you have a may have access to reason for the delay.

What documents you need to sign up

Have your Social Security number ready before you start. You will also need proof of citizenship or legal residency — a birth certificate, passport, or naturalization papers work. If you are signing up by phone or in person, bring a photo ID.

If you are not yet receiving Social Security benefits, you will need to provide information about your income and work history so Medicare can determine whether you may have access to for free Part A. If you worked outside the United States, bring records of that work as well.

If you are signing up online at Medicare.gov, you can create an account and upload documents, or you can complete the process without uploading and mail or fax documents later. The Social Security Administration will contact you if they need anything else.

Understanding Part A and Part B coverage

Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health services. You typically pay nothing for Part A if you or your spouse worked and paid Medicare taxes for at least 10 years. If you do not meet that requirement, Part A costs a monthly premium that varies based on how many quarters of work history you have.

Part B covers doctor visits, outpatient care, lab tests, X-rays, and some preventive services. Part B requires a monthly premium. The standard premium amount changes each year; you can find the current amount on Medicare.gov. Most people pay this premium through automatic deduction from their Social Security check.

Both Part A and Part B have deductibles and copayments. Part A has a deductible for hospital stays. Part B has an annual deductible, and then you typically pay 20 percent of the cost for most services after that. Many people buy a supplemental insurance plan (called Medigap) or a Medicare Advantage plan to cover these out-of-pocket costs.

What happens after you sign up

After you enroll, Medicare will mail you a Medicare card within two weeks. This card shows your Medicare number and which parts of Medicare you have. Keep it in a safe place — you will need it every time you see a doctor or go to the hospital.

Your coverage starts on the first day of the month in which you turn 65, or the first day of the month after you enroll, whichever is later. If you enroll during your Initial Enrollment Period before you turn 65, your coverage will start on the first day of the month you turn 65. If you enroll after your Initial Enrollment Period ends, your coverage starts the first day of the month after you enroll.

You will receive a welcome packet from Medicare that includes your card, a handbook explaining your coverage, and information about preventive services you can use at no cost. Read through this packet carefully, as it contains important details about how to use your benefits.

Late enrollment penalties and how to avoid them

If you do not sign up for Part B during your Initial Enrollment Period and you do not have other health coverage, you will pay a late enrollment penalty. This penalty is 10 percent of the standard Part B premium for each full 12-month period you were may be able to access but did not enroll. This penalty is permanent — you will pay it for as long as you have Part B.

You can avoid this penalty if you have creditable coverage — health insurance through an employer, a spouse's employer, or a union that is at least as good as Medicare Part B. If you have creditable coverage, you have eight months after that coverage ends to sign up for Part B without penalty. You will need to provide proof of this coverage when you enroll.

If you believe you have a valid reason for enrolling late, contact Medicare at 1-800-MEDICARE to discuss your situation. Valid reasons include not being a U.S. citizen or permanent resident during your Initial Enrollment Period, or not being told about the enrollment important date by Social Security or Medicare.

Signing up if you are still working

If you are still working and your employer has 20 or more employees, you may be able to delay Part B enrollment without penalty. This is called creditable coverage through your employer. You can sign up for Part A at 65, but you can wait to sign up for Part B until you leave your job or your employer coverage ends.

You must enroll in Part B within eight months after your employment ends or your employer coverage stops. If you do not, you will owe a late enrollment penalty. Make sure to tell Medicare about your employer coverage when you enroll so they can waive the penalty.

If your employer has fewer than 20 employees, you should sign up for Medicare Part B when you turn 65, even if you are still working. Your employer coverage will become secondary to Medicare, and you may face penalties if you delay.

Frequently Asked Questions

Can I sign up for Medicare before I turn 65?

Yes. You can start the enrollment process up to three months before you turn 65. Your coverage will begin on the first day of the month you turn 65. Signing up early gives you time to receive your Medicare card and learn how to use your benefits before coverage starts.

What if I miss my Initial Enrollment Period?

You can still enroll during the General Enrollment Period (January 1 through March 31 each year), but you will likely pay a permanent penalty on your Part B premium. The penalty is 10 percent of the standard premium for each 12-month period you were may be able to access but did not enroll. If you have creditable coverage through an employer or union, you may be able to enroll without penalty within eight months of losing that coverage.

Do I have to sign up for Part A and Part B at the same time?

No. You can sign up for Part A and Part B separately. However, if you do not sign up for Part B during your Initial Enrollment Period and you do not have other coverage, you will owe a late penalty. Most people sign up for both at the same time to avoid this penalty.

What should I ask my doctor before I turn 65?

Ask your doctor whether your current medications and treatments are covered by Medicare Part B. Ask which hospitals and specialists in your area accept Medicare. If you see specialists, confirm that they accept Medicare before you enroll. This helps you avoid surprises after your coverage starts.

When should I seek help signing up?

Contact Medicare at 1-800-MEDICARE if you have questions about your enrollment period, your coverage, or whether you owe a late penalty. You can also visit your local Social Security office or call 1-800-772-1213. If you need help in person, State Health Insurance information Programs (SHIP) offer free counseling — find yours at shiptalk.org.