When You Can Start Collecting Medicare: Age and Enrollment Rules

You can start Medicare at 65, but the exact month depends on your birthday

Medicare begins the month you turn 65, not on your birthday itself. If you turn 65 on any day in January, your coverage starts January 1. If you turn 65 on any day in February, your coverage starts February 1. You do not have to wait until the exact date to enroll — you can sign up during the three months before the month you turn 65.

Some people can start Medicare before 65. If you have been receiving Social Security disability benefits for 24 months, you become may be able to access at any age. If you have end-stage renal disease (permanent kidney failure) or ALS (Lou Gehrig's disease), you can start at any age as well. Otherwise, 65 is the standard starting age.

If you miss the window to enroll when you first become may be able to access, you can still sign up later, but you may pay a higher monthly premium for the rest of your life. The penalty is 10 percent of the Part B premium for each 12-month period you could have had it but did not enroll.

Key Takeaways

Medicare coverage begins the first day of the month in which you turn 65, regardless of the specific date of your birthday.
You can enroll during the three months before you turn 65, the month you turn 65, and the three months after — a seven-month window called your Initial Enrollment Period.
If you delay enrollment past this window without a valid reason, you will pay a permanent 10 percent monthly penalty on Part B premiums.
People under 65 who receive Social Security disability for 24 months, or who have end-stage renal disease or ALS, can start Medicare at any age.
If you are still working and have health insurance through your employer, you may be able to delay Part B enrollment without penalty.

Your Initial Enrollment Period: The seven-month window

Your Initial Enrollment Period is the only time you can enroll without penalty. It runs for seven months: 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, you can enroll from March through September.

You do not have to enroll in all parts of Medicare at once. Part A (hospital insurance) is usually automatic if you are already receiving Social Security. Part B (medical insurance) requires you to sign up during this window unless you have an exception. Part D (prescription drug coverage) has its own enrollment rules and important date.

If you enroll before the month you turn 65, your coverage will not start until that month arrives. There is no advantage to enrolling early except to make sure you do not miss the important date.

What happens if you miss your enrollment window

If you do not enroll in Part B during your Initial Enrollment Period, you can still sign up during the General Enrollment Period, which runs January 1 through March 31 each year. However, your coverage will not start until July 1 of that year, and you will pay a 10 percent penalty on your Part B premium for as long as you have Medicare.

The penalty applies even if you enroll years later. If you waited three years past your Initial Enrollment Period, you would pay 30 percent more than the standard premium. This penalty does not go away — it stays with you for life.

There is one exception: if you were covered by a group health plan through your own job (not your spouse's job) when you turned 65, you may have had a valid reason to delay Part B. In that case, you have eight months after your employment ends or the group coverage ends to enroll without penalty. You will need to show proof of that coverage when you sign up.

Enrolling before you turn 65

You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. You will need your Social Security number, proof of citizenship or legal residency, and information about any current health coverage you have.

If you are already receiving Social Security retirement or disability benefits, Part A is usually set up automatically three months before you turn 65. You will receive a Medicare card in the mail. Check it carefully — if your name, date of birth, or Social Security number is wrong, contact Social Security to correct it before your coverage starts.

Part B enrollment is separate. You must choose to enroll in Part B during your Initial Enrollment Period unless you have employer coverage that qualifies you for an exception. If you are unsure whether your coverage qualifies, contact Medicare before your enrollment window closes.

Starting Medicare while still working

If you are still working at 65 and have health insurance through your employer, you do not have to enroll in Part B right away. You can delay Part B enrollment without penalty as long as you are actively working and covered by a group health plan based on your current employment.

Coverage through a spouse's employer does not count as an exception — only your own job's coverage qualifies. Once you or your spouse retires or the group coverage ends, you have eight months to enroll in Part B without penalty. If you miss that important date, the 10 percent penalty applies.

You should still enroll in Part A when you turn 65, even if you delay Part B. Part A is hospital insurance and has no premium if you or your spouse paid Medicare taxes for 10 years. Enrolling in Part A does not affect your employer coverage.

Medicare for people under 65

If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you become may be able to access for Medicare at any age. Your coverage begins the 25th month of your disability benefit. You do not have to do anything — Medicare is set up automatically.

If you have end-stage renal disease (ESRD) or ALS, you can start Medicare right away, regardless of age. For ESRD, you can enroll as soon as you need dialysis or a kidney transplant. For ALS, you become may be able to access as soon as you are diagnosed. Contact Medicare directly to enroll, as these situations are not automatic.

If you are under 65 and do not fall into these categories, you cannot get Medicare. You would need to find coverage through the Health Insurance Marketplace, your employer, Medicaid, or another source.

What to expect after you enroll

You will receive your Medicare card in the mail about two weeks before your coverage starts. The card shows your Medicare number, which is usually your Social Security number followed by a letter. Keep this card safe — you will need it to see doctors and fill prescriptions.

Your coverage begins on the first day of the month you turn 65 (or the month your disability or ESRD may be able to access begins). You can start using your Medicare benefits that day, even if you have not received your physical card yet. If you need care before the card arrives, you can give your doctor your Medicare number from your enrollment confirmation.

Review your coverage choices during the year. If you did not enroll in Part D when you first became may be able to access, you can enroll during the Annual Enrollment Period (October 15 through December 7 each year) without penalty. If you want to change your Medicare plan, that same window applies.

Questions to ask your doctor or Medicare

Before your coverage starts, ask your current doctor whether they accept Medicare. Not all doctors do, and you may need to find a new provider. Ask whether any medications you take are covered under Medicare Part D, and whether you should enroll in a specific plan.

If you are still working, ask your employer's benefits office whether your group health plan qualifies as an exception to the Part B enrollment important date. Get the answer in writing, because you will need proof if you enroll late.

Contact Medicare at 1-800-MEDICARE if you are unsure about your enrollment important date, whether you may have access to for an exception, or what parts of Medicare you need. They can answer questions about your specific situation and help you enroll.

Frequently Asked Questions

Can I delay Medicare if I am still working?

You can delay Part B if you have health insurance through your own job, but you should still enroll in Part A at 65. Once you retire or lose that coverage, you have eight months to enroll in Part B without penalty. After that window closes, you pay a 10 percent penalty for life.

What if I turn 65 in the middle of the month?

Your Medicare coverage starts on the first day of the month you turn 65, regardless of the date. If you turn 65 on June 15, your coverage begins June 1. You can enroll anytime during the three months before that month.

Do I have to enroll in all parts of Medicare at once?

No. Part A is usually automatic. Part B requires you to enroll during your Initial Enrollment Period or face a penalty. Part D (prescription drugs) can be added later during the Annual Enrollment Period, but waiting may result in a penalty if you go without coverage.

What if I miss my enrollment important date?

You can still enroll during the General Enrollment Period (January 1 through March 31), but your coverage will not start until July 1, and you will pay a 10 percent monthly penalty on Part B for the rest of your life. The only exception is if you had may have access to employer coverage when you turned 65.

Can I get Medicare before I turn 65?

Yes, if you have been receiving Social Security disability for 24 months, or if you have end-stage renal disease or ALS. Otherwise, you must wait until 65. If you are under 65 and do not may have access to, you will need to find coverage through the Marketplace or another source.

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.