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Medicare Initial Enrollment Period Explained: When You Can Sign Up in 2026
Last Modified: 10/05/2026 | Reviewed by Keith Armbrecht (NPN 634015)
Quick Summary
Your Medicare Initial Enrollment Period, or IEP, is generally a 7-month window surrounding your 65th birthday.
It begins 3 months before the month you turn 65, includes your birthday month, and ends 3 months after your birthday month.
For many people, this is their first opportunity to enroll in Medicare Part A and Part B.
Signing up before your birthday month can help ensure your Medicare coverage begins when you turn 65.
Key Facts
- The Initial Enrollment Period usually lasts 7 months.
- It begins 3 months before your 65th-birthday month.
- It includes the month you turn 65.
- It ends 3 months after your birthday month.
- If your birthday is on the first day of the month, special timing rules apply.
- Enrolling before your birthday month generally allows Part B to begin the month you turn 65.
- If you enroll during your birthday month or one of the 3 months afterward, Part B generally begins the following month.
- Some people are automatically enrolled.
- People with qualifying active-employer coverage may be able to delay Part B.
- Missing your Initial Enrollment Period without qualifying for another enrollment period can result in delays and penalties.
How the 7-Month Enrollment Period Works
For most people turning 65:
3 months before your birthday month
↓
Month you turn 65
↓
3 months after your birthday month
Example
If you turn 65 on June 15:
Your Initial Enrollment Period generally begins:
March 1
and ends:
September 30
That gives you seven months to enroll.
When Does Coverage Start?
If you enroll in Part B:
During the 3 months before your birthday month
Coverage generally begins the first day of the month you turn 65.
During your birthday month
Coverage generally begins the following month.
During one of the 3 months after your birthday month
Coverage generally begins the month after you enroll.
What If Your Birthday Is on the First of the Month?
Medicare treats people born on the first day of a month differently for enrollment timing.
In that situation, Medicare eligibility generally begins the month before the month of your 65th birthday.
This shifts the Initial Enrollment Period earlier.
Video Explanation from Keith
Your Medicare Initial Enrollment Period Explained
Keith's Take
The Initial Enrollment Period sounds simple, but I see people make two common mistakes.
The first is waiting until the month they turn 65 to start the process.
If you know you need Medicare at 65, I generally prefer to see you begin planning during the three months before your birthday month.
The second mistake is assuming everyone needs to enroll at 65.
If you’re still working and have qualifying employer coverage, your situation may be different.
The key is knowing which enrollment rule applies to you before the deadline arrives.
Keith Armbrecht
Medicare on Video
Frequently Asked Questions About the Medicare Initial Enrollment Period
Q. How long is the Medicare Initial Enrollment Period?
A. Generally 7 months.
Q. When does it start?
A. Three months before the month you turn 65.
Q. When does it end?
A. Three months after the month you turn 65.
Q. Should I enroll before I turn 65?
A. If you need Medicare beginning when you turn 65, enrolling during the three months before your birthday month is generally the cleanest approach.
Q. What if I sign up during the month I turn 65?
A. Your Part B coverage generally starts the following month.
Q. What if my birthday is on the first day of the month?
A. Your Medicare timing generally moves one month earlier.
Q. Do I have to enroll if I'm still working?
A. Not necessarily. Qualifying employer coverage based on current employment may allow you to delay Part B.
Q. What happens if I miss my Initial Enrollment Period?
A. If you don't qualify for a Special Enrollment Period, you may have to wait until another enrollment period and could face a late enrollment penalty.
Official Government Sources
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