How Do I Qualify for a Part B Special Enrollment Period? A Special Enrollment Period (SEP) allows you to enroll in Medicare outside of the standard Medicare enrollment periods. The Part B SEP is available only if you have delayed enrollment in Part B because you have employer group coverage. For example, when you stop working or your employer group health coverage ends, you have an eight-month SEP to enroll in Part B without a late enrollment penalty.

If you meet the eligibility criteria and the Social Security Administration (SSA) grants you an SEP, your Medicare coverage will either be effective on the first of the month that you enroll, or on the first of the following month, depending on your specific situation. SEPs do not allow you to enroll in Medicare retroactively.

  • To obtain an SEP for Part B enrollment, contact the Social Security Administration (SSA) at 800-772-1213 and request the following two forms:
    • CMS 40B (Application for Enrollment in Medicare)
    • CMS L564 (Request for Employment Information)

Fill out and sign form CMS 40B and have your employer (or your spouse or family member’s employer) fill out form CMS L564. Once complete, bring both forms with an accompanying cover letter to your local Social Security office.

  • You are not entitled to a Part B SEP if you have had a lapse in coverage for more than eight consecutive months. A lapse in coverage is a period of time when you have neither Medicare Part B nor group health coverage based on current employment. For example, if you only had COBRA or retiree coverage at any time since you became eligible for Medicare, this is considered a lapse in coverage. If your lapse in coverage exceeds eight consecutive months, you are not eligible for an SEP.
  • If you qualify for Medicare based on disability, and you have a group health plan from your spouse or a family member, you are only eligible for an SEP if there are 100 or more people employed by the company. If the company employs fewer than 100 people, family members other than spouses are not eligible for the SEP.

There may be other ways you can enroll in Medicare Part B outside of an enrollment period, for instance, if you qualify for Equitable Relief or a Medicare Savings Program. For more information on SEP rules and Part B enrollment, contact your State Health Insurance Assistance Program (SHIP) by calling 877-839-2675 or visiting

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