The age you can start Medicare depends on your citizenship and work history

You can enroll in Medicare at age 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five consecutive years. If you have worked and paid Medicare taxes for at least 10 years (40 quarters), you may be able to enroll earlier in some cases — for example, if you receive Social Security Disability Insurance (SSDI) or have end-stage renal disease. The enrollment window opens three months before the month you turn 65 and closes three months after, so timing your enrollment matters to avoid penalties.

If you do not meet the citizenship or work history requirements, you may still purchase Medicare Part A and Part B directly, though the cost will be higher than the standard premium. Some people delay enrollment past 65 if they are still working and covered by an employer plan, which can actually lower your costs later.

Key Takeaways

  • 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 five consecutive years.
  • You must have paid Medicare taxes for at least 10 years (40 quarters) to enroll without paying a higher premium for Part A.
  • Your enrollment window is seven months long: three months before you turn 65, the month you turn 65, and three months after.
  • If you miss your enrollment window, you may owe a permanent penalty on your premiums unless you have a may have access to reason for the delay.
  • You can delay enrollment past 65 if you are covered by an active employer health plan, which may reduce your costs when you do enroll.

Who qualifies at 65

At age 65, you are may be able to access for Medicare if you are a U.S. citizen or a permanent resident (green card holder) who has lived in the United States for at least five consecutive years. You do not need to be retired or to have stopped working — age 65 is the threshold regardless of your employment status.

To enroll in Part A (hospital insurance) without paying a premium, you must have a work history: you or your spouse must have paid Medicare taxes for at least 10 years, which equals 40 quarters of coverage. If you do not have 40 quarters, you can still buy Part A, but you will pay a monthly premium. Part B (medical insurance) has a standard monthly premium that most people pay, and it increases if you delay enrollment without a valid reason.

Earlier enrollment if you receive disability benefits

You can enroll in Medicare before age 65 if you have been receiving Social Security Disability Insurance (SSDI) for 24 consecutive months. You become may be able to access on the first day of the 25th month of your SSDI benefits. This means you do not have to wait until 65 to have Medicare coverage — the program automatically transitions you at that point.

You can also enroll before 65 if you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant. With ESRD, you can enroll in Medicare regardless of age, though you will need to meet other requirements such as being a U.S. citizen or permanent resident. If you have ESRD, contact Social Security or your dialysis center to start the enrollment process.

Your seven-month enrollment window

Your Initial Enrollment Period (IEP) is seven months long and centers on the month you turn 65. It runs from three months before your birthday through three months after. For example, if you turn 65 in June, your window opens in March and closes in September. You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

Enrolling during this window protects you from penalties. If you miss it and do not have a may have access to reason — such as active employer coverage or membership in a Native American tribe — you will owe a permanent increase to your Part B premium. The penalty is 10 percent of the standard Part B premium for each full year you were may be able to access but did not enroll. This penalty stays with you for life, so enrolling on time is worth the effort.

What happens if you miss your enrollment window

If you do not enroll during your seven-month window, you enter a General Enrollment Period (GEP) that runs from January 1 to March 31 each year. You can enroll during this time, but your coverage does not start until July 1 of that year, creating a gap. You will also owe the permanent Part B premium penalty unless you have a may have access to reason for the delay.

may have access to reasons include being covered by an active employer health plan (yours or your spouse's), membership in a federally recognized Native American tribe, or living outside the United States. If you have one of these reasons, you can enroll without penalty during a Special Enrollment Period. You will need to provide proof — such as a letter from your employer showing your coverage dates — so keep those documents.

Delaying enrollment if you are still working

If you are still working at 65 and covered by your employer's health plan, you may want to delay Medicare enrollment. This is allowed, and it can actually save you money. If your employer has 20 or more employees, your employer plan is primary (it pays first), and Medicare is secondary. You do not need to enroll in Medicare yet.

When you do leave your job or lose employer coverage, you have eight months to enroll in Medicare without penalty — this is called your Special Enrollment Period. Your employer's human resources or benefits department can tell you whether your plan qualifies for this protection. Delaying enrollment while you have employer coverage is one of the few ways to avoid the permanent premium penalty for late enrollment.

Cost differences based on when you enroll

Your Part B premium increases by 10 percent for each full year you delay enrollment past 65, unless you have a may have access to reason. This penalty is permanent — it does not go away after a few years. For example, if the standard Part B premium is $165 per month and you delay three years, you will pay an extra $49.50 per month for the rest of your life.

Part A (hospital insurance) also has a penalty if you delay: it increases by 10 percent per year if you do not have 30 quarters of work history, and by 5 percent per year if you have 30 to 39 quarters. If you have the full 40 quarters, Part A has no premium and no penalty. These penalties explore only if you delay without a may have access to reason, so if you are covered by an employer plan, you are protected.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

Yes, if you have been receiving Social Security Disability Insurance for 24 months or if you have end-stage renal disease. Otherwise, you must wait until age 65. If you are still working and covered by an employer plan at 65, you can delay enrollment without penalty.

What if I miss my enrollment window by a few months?

You can enroll during the General Enrollment Period (January 1 to March 31 each year), but your coverage will not start until July 1. You will also owe a permanent penalty on your Part B premium unless you have a may have access to reason for the delay, such as active employer coverage.

Do I have to enroll in both Part A and Part B?

No. Part A (hospital insurance) and Part B (medical insurance) are separate. You can enroll in Part A only, Part B only, or both. However, delaying either one without a may have access to reason will result in a permanent premium penalty.

What counts as active employer coverage that lets me delay Medicare?

Your employer plan must be from a current employer (yours or your spouse's). If you are retired or your employer has fewer than 20 employees, the rules are different. Contact your employer's benefits department or call Medicare at 1-800-MEDICARE to confirm your situation.

Will I owe back premiums if I enroll late?

No, you will not owe premiums for the months you were not enrolled. However, you will owe the permanent penalty on your monthly premium going forward. Your coverage begins the month you enroll (or the month after, depending on when you enroll in that month).