Medicare starts at 65 for most people, but you may be able to enroll earlier if you have a disability or end-stage renal disease

You become may be able to access for Medicare at age 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five years. You do not have to be retired to enroll — Medicare is based on age, not work status. However, three groups of people can start Medicare before 65: those with a disability, those with end-stage renal disease (ESRD), and those with amyotrophic lateral sclerosis (ALS).

The month you turn 65, you enter your Initial Enrollment Period, which runs for three months before your birthday month, during your birthday month, and for three months after. If you miss this window, you will pay a permanent penalty on your Part B and Part D premiums for as long as you have Medicare. The penalty is 10 percent per year for each 12-month period you were may be able to access but did not enroll.

Key Takeaways

  • You can enroll in Medicare starting three months before you turn 65, during the month you turn 65, or up to three months after your birthday.
  • If you miss your Initial Enrollment Period, you will pay a permanent surcharge on your Part B and Part D premiums for the rest of your time on Medicare.
  • You may be able to start Medicare before 65 if you receive Social Security disability benefits, have end-stage renal disease, or have been diagnosed with ALS.
  • If you are still working and have health insurance through your employer, you may be able to delay enrollment without penalty under certain conditions.

Starting Medicare at 65: Your enrollment window

Your Initial Enrollment Period is seven months long and centered on your 65th birthday month. You can enroll during the three months before you turn 65, the month of your birthday, or the three months after. For example, if you turn 65 in June, you can enroll from March through September.

You enroll through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. You will need your Social Security number and information about any current health coverage. Enrollment takes about 10 minutes online. Your coverage will begin on the first day of the month in which you turn 65, or the first day of the following month if you enroll after your birthday month.

If you enroll before your birthday month, your coverage starts the first of that month. If you enroll during your birthday month, coverage starts the first of the next month. If you enroll after your birthday month, coverage starts the first of the month after you enroll. Plan ahead so your new coverage does not overlap with old coverage and create gaps.

Medicare before 65: Disability, ESRD, and ALS

You can start Medicare at any age if you have been receiving Social Security Disability Insurance (SSDI) for 24 months. You do not have to wait until month 25 — you can enroll during your Initial Enrollment Period, which begins three months before the 24-month mark. This means you could be on Medicare before you have technically been on SSDI for two full years.

If you have end-stage renal disease (ESRD), you can start Medicare when ready, regardless of age. ESRD means your kidneys function at less than 15 percent of normal capacity or you need dialysis. You will need documentation from your doctor or dialysis center. Coverage begins the first of the month in which you start dialysis or the month after you receive a kidney transplant.

If you have been diagnosed with amyotrophic lateral sclerosis (ALS), you can start Medicare right away without waiting for SSDI approval. You will need a letter from your doctor confirming the diagnosis. ALS is the only condition that bypasses the usual waiting periods.

What happens if you miss your enrollment important date

If you do not enroll during your Initial Enrollment Period and you do not have a may have access to reason for a late enrollment, you will face a permanent Part B penalty of 10 percent for each 12-month period you were may be able to access but did not enroll. If you were may be able to access for three years and did not enroll, your penalty would be 30 percent, and you would pay that surcharge for the rest of your life on Medicare.

The same 10 percent annual penalty applies to Part D (prescription drug coverage). If you go 63 days or more without Part D coverage and you do not have other creditable drug coverage, you will owe this penalty when you finally enroll.

You can enroll late without penalty only if you have a may have access to life event — such as losing employer health coverage, moving out of your plan's service area, or becoming a U.S. citizen. You must enroll within two months of the event. If you were covered by an employer plan with 20 or more employees while you were still working, you may also be able to delay without penalty.

Delaying enrollment if you have employer coverage

If you are still working and your employer offers health insurance, you may be able to delay Medicare enrollment without paying a penalty. This is called creditable coverage. Your employer plan must be based on your current employment (not retiree coverage), and your employer must have at least 20 employees.

When you do leave your job or lose the employer coverage, you have eight months to enroll in Medicare without penalty. This is called your Special Enrollment Period. You will need to show proof that you had employer coverage — usually a letter from your employer's benefits office stating the coverage dates and that it was based on current employment.

If you are unsure whether your plan qualifies, contact your employer's benefits department or call Medicare at 1-800-MEDICARE. It is worth checking before you miss your Initial Enrollment Period, because the penalty is permanent.

How to enroll in Medicare

You can enroll online at Medicare.gov, by calling 1-800-MEDICARE (1-800-633-4227), or by visiting your local Social Security office. Online enrollment is fastest — you can complete it in one session and see your confirmation when ready. The phone line has wait times that vary by time of day; early morning or mid-week calls are usually shorter.

Have your Social Security number, date of birth, and information about any current health coverage ready. If you are enrolling for ESRD or ALS, have your doctor's documentation available. The process takes about 10 minutes. You will receive a Medicare card in the mail within two weeks, though your coverage begins on the date you are approved, not when the card arrives.

If you are already receiving Social Security benefits, your enrollment may happen automatically. Social Security will send you a notice if you are may be able to access and have not yet enrolled. You can still choose to enroll yourself if you want to do it sooner.

Medicare Parts A, B, C, and D: What you are enrolling in

Part A covers hospital stays, skilled nursing care, and hospice. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes while working. Part B covers doctor visits, outpatient care, and some preventive services. Part B has a monthly premium that changes each year — in 2024 it is $174.70 for most people, but higher earners pay more.

Part C (Medicare Advantage) is an alternative to Original Medicare that combines Parts A, B, and usually D through a private insurance company. Part D is prescription drug coverage. You enroll in Part D separately, and if you go without it when you are first may be able to access, you will pay a penalty when you do enroll.

When you enroll in Medicare, you will choose between Original Medicare (Parts A and B) or Medicare Advantage (Part C). If you choose Original Medicare, you will also need to choose a Part D plan for prescriptions. These choices do not have to be made all at once — you can enroll in Part A and B first, then add Part D later during the enrollment period, though waiting may cost you the penalty.

Frequently Asked Questions

What if I turn 65 while I am still working?

You can enroll in Medicare even if you are still working. If your employer offers health insurance, you may be able to delay Part B enrollment without penalty as long as you have creditable coverage based on current employment. Part A (hospital coverage) has no penalty for delay, so many people enroll in Part A only and add Part B later.

Can I enroll in Medicare online, or do I have to go to an office?

You can enroll entirely online at Medicare.gov. You can also call 1-800-MEDICARE or visit a Social Security office in person. Online enrollment is usually fastest and you get confirmation when ready. The phone line has wait times that vary by time of day.

What if I miss my Initial Enrollment Period but I have a good reason?

If you have a may have access to life event — such as losing employer coverage, moving, or becoming a citizen — you have two months to enroll without penalty. You will need to provide proof of the event. If you do not have a may have access to reason, the 10 percent annual penalty applies permanently.

Do I have to choose a Medicare Advantage plan, or can I stay with Original Medicare?

You can choose either. Original Medicare (Parts A and B) lets you see any doctor who accepts Medicare. Medicare Advantage (Part C) is through a private insurance company and usually has lower premiums but requires you to use doctors in the plan's network. You can switch between them during the annual enrollment period.

When will my Medicare card arrive after I enroll?

Your Medicare card arrives in the mail within two weeks of approval, but your coverage begins on the date you are approved, not when the card arrives. You can use your approval notice as proof of coverage until the card comes. You can also view your coverage information online at Medicare.gov.