When you are first eligible for Medicare you have a 7-month Initial Enrollment Period to sign up for Part A and/or Part B.
For example, if you're eligible for Medicare when you turn 65, you can sign up during the 7-month period that:
Begins 3 months before the month you turn 65
Includes the month you turn 65
Ends 3 months after the month you turn 65
If you aren’t automatically enrolled, you can sign up for free Part A (if you’re eligible) any time during or after your Initial Enrollment Period starts. Your coverage start date will depend on when you sign up. If you have to buy Part A and/or Part B, you can only sign up during a valid enrollment period.
Important to note: Signing up late for part B (after your initial eligibility period) could mean you pay a late enrollment penalty and this fee will be included for as long as you have Part B. Not to mention you will have a gap in coverage.
General Open Enrollment each year is between January 1–March 31 You can sign up for Part A and/or Part B.
You must pay premiums for Part A and/or Part B. Your coverage will start July 1. You may have to pay a higher premium for late enrollment in Part A and/or a higher premium for late enrollment in Part B.
You can sign up during General Enrollment Period between January 1–March 31 each year if both of these apply:
Part B Sign Up:
To sign up for Part B, complete an Application for Enrollment in Part B (CMS-40B). Get this form and instructions in Spanish. If you don't have Medicare or you want to sign up for Part A (some people have to pay a premium for Part A), contact Social Security.
Special circumstances (Special Enrollment Periods)
Once your Initial Enrollment Period ends, you may have the chance to sign up for Medicare during a Special Enrollment Period (SEP). If you're covered under a group health plan based on current employment, you have a SEP to sign up for Part A and/or Part B anytime as long as:
You also have an 8-month SEP to sign up for Part A and/or Part B that starts at one of these times (whichever happens first):
Usually, you don't pay a late enrollment penalty if you sign up during a SEP.
COBRA and Retiree Plans
COBRA and retiree health plans aren't considered coverage based on current employment. You're not eligible for a Special Enrollment Period when that coverage ends. This Special Enrollment Period also doesn't apply to people who are eligible for Medicare based on having End-Stage Renal Disease (ESRD).
If you have a Health Savings Account (HSA) with a High Deductible Health Plan (HDHP) based on your or your spouse’s current employment, you may be eligible for an SEP.
To avoid a tax penalty, you should stop contributing to your HSA at least 6 months before you apply for Medicare. You can withdraw money from your HSA after you enroll in Medicare to help pay for medical expenses (like deductibles, premiums, coinsurance or copayments).