You can start Medicare at 65, but the exact timing depends on your work status and whether you have other health coverage

Most people become may be able to access for Medicare on the first day of the month they turn 65. If you are still working and covered by your employer's health plan, you can delay starting Medicare without penalty — but you must tell Social Security you are doing so. If you are retired or no longer have employer coverage, you should start Medicare during your initial enrollment window, which runs from three months before your 65th birthday through three months after. Missing this window can mean permanent late-enrollment penalties on your premiums.

The rules are different if you are on Social Security disability benefits or have end-stage renal disease. People on disability automatically move to Medicare at 65 without having to do anything. Those with kidney failure can start Medicare earlier, regardless of age. Understanding which rule applies to you prevents costly gaps in coverage.

Key Takeaways

  • Your initial enrollment window for Medicare is seven months long: three months before you turn 65, the month you turn 65, and three months after.
  • If you are still working and have health coverage through your job, you can delay Medicare without penalty, but you must notify Social Security in writing.
  • Missing your initial enrollment window can result in a permanent 10 percent increase to your Part B premium for each year you delayed.
  • People receiving Social Security disability benefits are automatically enrolled in Medicare at 65 and do not need to take action.
  • You can start Medicare as early as age 60 if you have end-stage renal disease or are a dialysis patient, regardless of work status.

The standard enrollment window: three months before and after age 65

Your initial enrollment period is a seven-month window centered on your 65th birthday. It begins three months before the month you turn 65 and ends three months after. During this time, you can start Medicare Part A (hospital insurance) and Part B (medical insurance) without waiting or paying a penalty.

You do not have to start on your birthday itself. Many people start on the first day of the month they turn 65, but you can start any month within the window. The key is to make your choice and notify Social Security before the window closes. If you turn 65 in June, your window runs from March through September. If you miss September, you enter a different set of rules.

What happens if you miss your initial enrollment window

If you do not start Medicare during your initial enrollment period and you do not have a valid reason to delay, you will face a late-enrollment penalty. For Part B, this penalty is 10 percent of the standard premium for each full year you delayed. The penalty is permanent — it stays on your premium for as long as you have Medicare.

The same penalty applies to Part D (prescription drug coverage) if you go without it for more than 63 days in a row. Part A typically has no penalty if you delay, but if you have worked long enough to may have access to without paying premiums, delaying does not hurt you. If you have to pay for Part A, a late-enrollment penalty of 10 percent applies there as well.

You can avoid this penalty if you have what Medicare calls creditable coverage — health insurance through your current job, your spouse's job, or COBRA that is as good as or better than Medicare. You must be able to prove you had this coverage during the months you were not enrolled in Medicare.

Staying on employer coverage past 65

If you are still working and your employer offers health insurance, you can keep that coverage and delay Medicare. This is common for people who work past 65 or whose employers offer retiree health plans. You do not lose your right to start Medicare later without penalty, as long as you have employer coverage the whole time.

When you do stop working or lose employer coverage, you have an eight-month window to start Medicare without penalty. This window begins the month your employment ends or your coverage stops. You must tell Social Security in writing that you are delaying Medicare due to current employment. A phone call or online message is not enough — send a letter or use the form at your local Social Security office.

If your employer has 20 or more employees, Medicare is the secondary payer while you work, meaning your employer plan pays first. If your employer has fewer than 20 employees, Medicare is primary. Either way, you can coordinate the two plans to avoid gaps.

Automatic enrollment if you receive Social Security

If you are already receiving Social Security retirement or disability benefits when you turn 65, you are automatically enrolled in Medicare Part A and Part B. Social Security will send you a Medicare card in the mail about two months before your 65th birthday. You do not need to do anything, and you cannot opt out of Part A.

You can refuse Part B if you are still working and have employer coverage, but you must do so in writing within two months of receiving your card. If you refuse and later change your mind, you can start Part B during the general enrollment period (January 1 through March 31 each year), but you will pay a late-enrollment penalty.

If you are not yet receiving Social Security when you turn 65, you must contact Social Security yourself to start Medicare. Do this during your initial enrollment window, either online at Social Security's website, by phone at 1-800-772-1213, or in person at your local office.

Early Medicare for kidney disease and disability

You can start Medicare before 65 if you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant. You become may be able to access the month dialysis treatment begins or the month you receive a kidney transplant, whichever comes first. You can start Medicare as early as age 60 if you meet this condition.

People who have been receiving Social Security Disability Insurance (SSDI) for 24 months automatically move to Medicare at age 65. You do not need to do anything — the transition happens automatically. If you are on SSDI and approaching 65, expect your Medicare card to arrive in the mail about two months before your birthday.

If you have ESRD, you must still choose your coverage during an enrollment period. Contact Social Security or Medicare to start the process as soon as your kidney condition is diagnosed, because the enrollment window rules still explore.

Coordinating Medicare with other coverage

If you have retiree health coverage from a former employer, you can keep it and start Medicare at 65. The two plans will coordinate — Medicare pays its share, then the retiree plan pays its share. You do not have to choose between them.

If you have coverage through a spouse's employer, the same coordination rules explore. Your spouse's plan remains primary until you turn 65, at which point Medicare becomes primary for you. Make sure both plans know about each other to avoid billing confusion.

If you are covered by COBRA (continuation coverage from a former employer), that coverage ends at 65 or after 18 months, whichever comes first. Plan to start Medicare before COBRA ends so you do not have a gap. COBRA is considered creditable coverage, so you will not face a late-enrollment penalty if you start Medicare when COBRA ends.

Frequently Asked Questions

Can I start Medicare before I turn 65?

You can start at 60 if you have end-stage renal disease requiring dialysis or a transplant. Otherwise, you must wait until 65. If you are on Social Security Disability Insurance, you automatically move to Medicare at 65 without having to do anything.

What if I am still working at 65 and do not want Medicare yet?

You can delay if you have health coverage through your current job. You must notify Social Security in writing that you are delaying due to current employment. When you stop working or lose coverage, you have eight months to start Medicare without penalty.

Do I have to take Part B, or can I just take Part A?

You can take Part A alone if you are not receiving Social Security benefits yet. If you are already on Social Security, you are automatically enrolled in both Part A and Part B, but you can refuse Part B in writing within two months of receiving your card if you have employer coverage.

What is the late-enrollment penalty, and how long does it last?

The penalty is 10 percent of the standard Part B premium for each full year you delayed starting. The penalty is permanent and stays on your premium for as long as you have Medicare. You can avoid it by proving you had creditable coverage during the months you were not enrolled.

If I miss my enrollment window, can I still start Medicare later?

Yes, but you will pay a late-enrollment penalty unless you had creditable coverage. You can start during the general enrollment period (January 1 through March 31) each year, but the penalty applies. The only way to avoid it is to prove you had health coverage as good as Medicare during the time you were not enrolled.