Your Initial Enrollment Period: When to Sign Up at 65 and When Coverage Starts

Your Initial Enrollment Period (IEP) is your first and best chance to sign up for Medicare. It is 7 months long: the 3 months before the month you turn 65, the month you turn 65, and the 3 months after. When you sign up inside that window decides when your coverage starts.

If your 65th birthday is in January 2027, your window opened October 1, 2026. It is open right now.

When is my Initial Enrollment Period?

Find your birthday month in the table. These windows apply if your birthday is on the 2nd or later; if it falls on the 1st, see the section below.

Our Medicare enrollment calculator works out your exact window and start dates from your birth date.

When does coverage start if I sign up in each month?

The rule is simple. Sign up before your birthday month and coverage starts the 1st of your birthday month. Sign up during or after your birthday month and coverage starts the 1st of the following month.

Here is how that plays out for someone turning 65 on January 15, 2027:

This "month after" rule has applied since January 1, 2023. Before then, people who signed up late in their window could wait up to 3 months for coverage, so older advice you read online may be out of date.

What if my birthday is on the 1st?

Medicare treats you as turning 65 the month before. Your window starts 4 months before your birthday month and ends 2 months after it. Medicare & You 2027 gives this example: if you turn 65 on June 2, your window runs March through September; if you turn 65 on June 1, it runs February through August.

With a June 1 birthday, signing up in February, March or April starts your coverage on May 1. Signing up in May or later starts it the 1st of the month after you sign up.

Will I be enrolled automatically?

You will be enrolled in Parts A and B automatically if you have been getting Social Security or Railroad Retirement Board benefits for at least 4 months before you turn 65. Your red, white and blue Medicare card arrives in the mail about 3 months before your 65th birthday.

If you are auto-enrolled but do not want Part B yet (for example, you are still covered at a large employer), you must tell Social Security before the coverage start date on your card. If you do nothing, you keep Part B and the premium ($202.90 a month in 2026) comes out of your benefit.

Many people now wait past 65 to claim Social Security. If that is you, nothing happens automatically. You have to apply.

How do I sign up during my Initial Enrollment Period?

You apply through Social Security, not Medicare. You have three options:

1. Online at Social Security's Medicare sign-up page. Medicare.gov calls this the easiest and fastest way.
2. By phone at 1-800-772-1213 (TTY 1-800-325-0778).
3. In person at your local Social Security office.

If you worked for a railroad, contact the Railroad Retirement Board at 1-877-772-5772 instead. After your application is processed, your Medicare card comes in the mail.

Should I sign up for Part B at 65 if I am still working?

It depends on your employer's size and the kind of coverage you have. If you or your spouse are actively working and the employer has 20 or more employees, the group plan pays first and you can usually delay Part B without a penalty. When that coverage or the job ends, you get an 8-month Special Enrollment Period.

If the employer has fewer than 20 employees, Medicare pays first, and your group plan may pay little or nothing for care Part B would have covered. COBRA, retiree coverage, VA coverage and individual Marketplace plans do not count as current employment coverage. Read working past 65 and employer coverage vs Medicare before you skip Part B.

What else should I choose during my Initial Enrollment Period?

Your IEP is also when you pick how to fill Medicare's gaps:

• Part D or Medicare Advantage. You can join either during the same 7 months. Going 63 days or more without Part D or other creditable drug coverage after your IEP can trigger a Part D penalty.
• Medigap. Your separate 6-month Medigap Open Enrollment Period starts the first month you are 65 and have Part B. During it, insurers in Nebraska cannot turn you down or charge more for health conditions.
• A trial run of Medicare Advantage. If you join a Medicare Advantage plan when first eligible at 65, you can drop it within 12 months, return to Original Medicare and buy a Medigap policy with guaranteed issue rights.

For a month-by-month plan for the year before your birthday, see the turning 65 checklist for Nebraska.

What happens if I miss my Initial Enrollment Period?

Without qualifying employer coverage, your next chance to get Part B is usually the General Enrollment Period, January 1 to March 31, with coverage starting the month after you sign up. You could go months uninsured, and you will likely owe a Part B penalty of 10% for each full 12 months you could have had Part B. That penalty lasts as long as you have Part B.

See the numbers in late enrollment penalties, or try the Part B penalty calculator. If you lost Medicaid, were affected by a disaster, or got wrong information from an employer or plan, ask about an exceptional-condition Special Enrollment Period.

Questions about your dates? Call 1-800-MEDICARE (1-800-633-4227), available 24 hours a day, 7 days a week (TTY 1-877-486-2048), or Nebraska SHIP at 1-800-234-7119.