If your 65th birthday is in December 2026, you have a 7-month window to enroll in Medicare. Here are your exact dates — and the deadline to avoid any gap in coverage.
Quick answer: If you turn 65 in December 2026, your 7-month Initial Enrollment Period runs September 1, 2026 – March 31, 2027. To have Medicare active the month you turn 65, sign up on or before November 30, 2026 — that is, during the three months before December. Sign up later and your coverage start date slips, as shown below.
Turning 65 in December 2026 means your one-time Medicare Initial Enrollment Period runs from September 1, 2026 to March 31, 2027. The smart deadline is November 30, 2026 — sign up by then and your Medicare is active on December 1, 2026. Miss the whole window and you can face a permanent late-enrollment penalty. Here is exactly when to act and when your coverage begins.
Your Initial Enrollment Period for turning 65 in December 2026 is exactly seven months long. It opens on September 1, 2026 (three months before December), includes all of December, and closes on March 31, 2027 (three months after). You can sign up for Part A, Part B, and a Part D drug plan or a Medicare Advantage plan during this window. The single most important date is November 30, 2026: enroll on or before it and your coverage starts December 1, 2026, the day your birthday month begins, with no gap.
Under the rule in effect since January 1, 2023, your Part B coverage start date depends on when during your IEP you sign up:
| If you sign up… | Coverage starts |
|---|---|
| The 3 months before (September–November 2026) | December 1, 2026 (1st of your birthday month) |
| During December 2026 (your birthday month) | January 1, 2027 |
| During January 2027 (month 1 after) | February 1, 2027 |
| During February 2027 (month 2 after) | March 1, 2027 |
| During March 2027 (month 3 after) | April 1, 2027 |
Note: if your birthday falls on the 1st of December, Medicare counts you as turning 65 the previous month, so every date above shifts one month earlier.
The most common mistake is waiting until December — your actual birthday month — to sign up. If you do, your coverage won't start until January 1, 2027, leaving you a month without Medicare even though you were eligible. Enroll during the three months before December (any time from September 1, 2026 through November 30, 2026) and your Part A and Part B begin on December 1, 2026. There is no advantage to waiting, and signing up early is free.
Enter your date of birth and our free calculator shows your precise IEP dates and coverage start — no signup, no email.
Open the Sign-Up Window Calculator →If you don't enroll by March 31, 2027 and you don't qualify for a Special Enrollment Period (for example, because you had creditable employer coverage), you generally have to wait for the General Enrollment Period (January 1 – March 31) and may owe a permanent Part B late-enrollment penalty — 10% of the premium for each full 12 months you delayed — plus a separate Part D penalty. See the late-enrollment penalty calculator for what that costs over a lifetime, and the enrollment finder if you think a Special Enrollment Period applies to you.
Sign up during the three months before December — any time from September 1, 2026 through the last day of November — to have Part A and Part B active on December 1, 2026, the first day of your birthday month. Your full window stays open until March 31, 2027, but enrolling later delays your coverage start.
If your employer has 20 or more employees and you have creditable group coverage, you can usually delay Part B without a penalty and get an 8-month Special Enrollment Period when that coverage ends. Many people still take premium-free Part A at 65. See working past 65 →
No. Your IEP (September 1, 2026 – March 31, 2027) is your one-time window around turning 65. AEP (October 15 – December 7 every year) is for people who already have Medicare and want to change Advantage or Part D plans. See all enrollment periods →
If you were born on the 1st, Medicare treats you as turning 65 the previous month, so your whole IEP and eligibility shift one month earlier. Confirm your exact dates with the sign-up window calculator or at SSA.gov.
A clean, dated sign-up timeline is the fastest way to get a T65 prospect to act. This page is free to share with clients. The Turning 65 Medicare Enrollment Kit gives them a printable checklist and worksheet so they never miss their window — and the T65 Pipeline Tracker helps you work the whole book.
See Medicare agent tools on Etsy →These dates are based on U.S. government enrollment rules: