Enrollment Guide • Updated 2026

Medicare Enrollment Deadlines 2026 — Complete Timeline

✓ Updated 2026 · ✓ IEP, SEP & Open Enrollment · ✓ How to Avoid Penalties

Medicare enrollment has multiple windows, each with different rules and consequences for missing them. Understanding your specific deadlines is one of the most important things you can do before turning 65.

🚨 Penalties are permanent. Unlike most financial penalties, Medicare late enrollment penalties stay for life. A 2-year delay in enrolling in Part B adds 20% to your monthly premium — every month — for as long as you have Medicare.

Your Initial Enrollment Period (IEP)

The IEP is your first and most important enrollment window. It is 7 months long:

Month	Action	Coverage Start
3 months before your 65th birthday month	Enroll here for best timing	Month you turn 65
2 months before your 65th birthday month	Enroll	Month you turn 65
1 month before your 65th birthday month	Enroll	Month you turn 65
Your 65th birthday month	Enroll	Following month
1 month after your 65th birthday month	Enroll	2 months later
2 months after your 65th birthday month	Enroll	3 months later
3 months after your 65th birthday month	Last chance in IEP	3 months later

Special Enrollment Period (SEP)

If you are covered by employer health insurance when you turn 65 (through your job or your spouse’s job), you can delay Medicare Part B without penalty. This is called having a qualifying Special Enrollment Period. When you retire or lose employer coverage you have 8 months to enroll in Part B without penalty. You do not need to wait for the next General Enrollment Period.

⚠ COBRA does not count. COBRA coverage after leaving employment does not qualify as employer insurance for SEP purposes. If you are on COBRA your 8-month SEP clock started when your active employer coverage ended — not when COBRA ends.

Medigap Open Enrollment Period

Your Medigap (Medicare Supplement) Open Enrollment Period begins the month you are both 65 or older AND enrolled in Medicare Part B. During this 6-month window insurance companies must sell you any plan they offer at the standard rate regardless of your health history. Outside this window most states allow medical underwriting — meaning you can be charged more or denied coverage based on pre-existing conditions.

General Enrollment Period (GEP)

If you miss your IEP and do not have a qualifying SEP, you must wait for the General Enrollment Period — January 1 through March 31 each year. Coverage starts July 1. You will pay the late enrollment penalty permanently.

Annual Enrollment Period (AEP)

October 15 through December 7 every year. During the AEP you can switch Medicare Advantage plans, switch Part D drug plans, join or leave Medicare Advantage, or join a Part D plan. Changes take effect January 1.

Medicare Advantage Open Enrollment Period

January 1 through March 31 each year. If you are already enrolled in a Medicare Advantage plan you can switch to a different Advantage plan or return to Original Medicare (and enroll in a Part D plan). You cannot use this period to join Medicare Advantage from Original Medicare.

Calculate your exact enrollment deadlines

Enter your birthday and our free tool shows all your key Medicare dates.

Calculate My Deadlines →