When You Can Enroll in Medicare: Age Requirements and Timing

You can enroll in Medicare at 65, or earlier if you have a disability or end-stage renal disease

Most people become may be able to access for Medicare the month they turn 65. If you were born on the first of the month, your coverage starts the month before. If you were born on any other day, coverage starts the month you turn 65. You do not have to wait until your birthday itself — the month matters, not the exact date.

You can also get Medicare before 65 if you have been receiving Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS). These are the only three routes to Medicare before age 65.

Enrollment is not automatic for most people. You must sign up during your enrollment period, or you may face a permanent penalty on your premiums. The rules for when you can enroll depend on your age and your work history.

Key Takeaways

You become may be able to access for Medicare at 65, and coverage begins the month you turn 65 (or the month before if you were born on the first of the month).
You can enroll before 65 only if you have been on SSDI for 24 months, have end-stage renal disease, or have ALS.
You must enroll during your initial enrollment period or a general enrollment period, or you will pay a higher premium for as long as you have Medicare.
If you are still working and have health insurance through your job, you may be able to delay enrollment without penalty under certain conditions.
Your enrollment period is a seven-month window centered on your birthday month — three months before, the month you turn 65, and three months after.

The initial enrollment period: when you must sign up

Your initial enrollment period is a seven-month window: three months before the month you turn 65, the month you turn 65, and three months after. For example, if you turn 65 in June, your period runs from March through September.

You should enroll during this window. If you miss it and do not have a valid reason, you will pay a higher premium for Part B (doctor and outpatient care) for the rest of your life. 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. If you were may be able to access for eight years without signing up, you would pay 80 percent more than the standard rate, permanently.

The same penalty applies to Part D (prescription drug coverage) if you go without it for 63 or more days in a row. Once you have a gap, the penalty stays with you even after you enroll.

Working past 65 and delaying enrollment

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 the special enrollment period for people with group health plan coverage. You must have actual coverage through your employer — not just may be able to access — and your employer must be based in the United States.

Under this rule, you can wait to enroll in Part B until you leave your job or lose your employer coverage, whichever comes first. You then have eight months from the month your coverage ends to enroll without penalty. This applies only to Part B; Part A (hospital insurance) has different rules and you should check with Social Security about your specific situation.

If your employer has fewer than 20 employees, this exception does not explore. You must enroll during your initial enrollment period or pay the penalty, even if you have coverage through work.

Enrolling before 65 with a disability or serious illness

If you have been receiving SSDI for 24 months, you become may be able to access for Medicare automatically. You do not need to explore separately. Your coverage begins in the 25th month of your SSDI payments. Social Security will contact you about three months before your coverage starts.

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — you can enroll in Medicare regardless of age. Your coverage can begin the month dialysis starts, the month you have a transplant, or the month you are referred for dialysis, whichever comes first. You must enroll within 12 months of one of these events.

If you have ALS (Lou Gehrig's disease), you become may be able to access for Medicare when ready upon approval of your SSDI claim. You do not have to wait 24 months. Medicare coverage begins the same month your SSDI benefits begin.

How to enroll: the main routes

You can enroll in Medicare through Social Security, Medicare.gov, or by phone. Social Security handles enrollment for people already receiving benefits. If you are not yet receiving Social Security retirement or disability benefits, you can enroll through Medicare.gov or by calling 1-800-MEDICARE.

You can enroll online at Medicare.gov, by phone, by mail, or in person at a Social Security office. Online enrollment is usually the fastest. You will need your Social Security number, proof of citizenship or legal residency, and information about any current health coverage.

If you enroll online or by phone during your initial enrollment period, your coverage typically begins the first day of the month you turn 65 (or the first day of the month before, if you were born on the first). If you enroll after your initial period ends, there may be a delay before coverage starts.

General enrollment period: if you missed your initial window

If you miss your initial enrollment period, you can still enroll during the general enrollment period, which runs from January 1 through March 31 each year. However, your coverage will not begin until July 1 of that year, and you will pay the permanent penalty on Part B premiums.

The general enrollment period is a safety net, but it comes with a cost. You will have a gap in coverage from when you became may be able to access until July. During that gap, you are responsible for all medical bills. It is far better to enroll during your initial period.

Special situations: life changes and coverage gaps

If you experience certain life changes — such as losing employer coverage, moving out of your health plan's service area, or having your plan end — you may may have access to for a special enrollment period outside the normal windows. These periods usually last two months and let you enroll without penalty.

You must report the change to Medicare within 60 days of losing coverage. If you wait longer, you may lose the special enrollment period and have to wait for the general enrollment period, which means a gap in coverage and a permanent penalty.

If you are receiving unemployment benefits, you may also have a special enrollment period. Contact Social Security or Medicare directly to find out whether your situation qualifies.

Frequently Asked Questions

What happens if I turn 65 but do not enroll in Medicare?

You will not automatically lose anything, but you will start owing a penalty on Part B premiums that increases the longer you wait. If you have no other coverage and go without Medicare, you will pay all medical bills out of pocket. The penalty stays with you for life, even after you enroll.

Can I enroll in Medicare before I turn 65 if I am not disabled?

No. The only ways to get Medicare before 65 are SSDI for 24 months, end-stage renal disease, or ALS. If you do not have one of these, you must wait until 65. If you need coverage before then, you may be able to buy a plan through the health insurance marketplace.

If I am still working at 65, do I have to enroll in Medicare?

If your employer has 20 or more employees and you have coverage through them, you can delay Part B without penalty. Part A (hospital insurance) has different rules — check with Social Security about whether you must enroll. If your employer has fewer than 20 employees, you must enroll during your initial period or pay the penalty.

What if I miss my initial enrollment period by a few weeks?

You will have to wait for the general enrollment period (January 1 through March 31) to enroll, and your coverage will not start until July 1. You will also pay a permanent penalty on Part B premiums. There is no grace period — the seven-month initial window is firm.

Do I have to enroll in Part D when I turn 65?

You do not have to, but if you go without prescription drug coverage for 63 or more days in a row, you will pay a penalty for as long as you have Medicare. If you do not take prescription drugs now, you can wait, but sign up before you need coverage to avoid the penalty.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.