Common Medicare Enrollment Forms and When to Use Them
MEDICARE FORMS FAQ
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Yes — depending on your situation, you may need to submit additional Medicare forms beyond the standard application. Below are the most common forms, when to use them, and what each one does.
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If you’re still working at age 65 and have creditable employer coverage, you may choose to enroll in Part A only (since it’s usually premium-free).
• Use Form CMS-18-F-5
• Always confirm whether enrolling in Part A only is appropriate for your situation, especially if contributing to an HSA.
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If you delayed Part B because you had employer coverage, but already have Part A, use:
• Form CMS-40B
• This allows you to enroll in Part B only after losing or leaving group coverage
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If you’re retiring and not yet enrolled in Medicare, or if you’re over 65 and never signed up before:
• Use Form CMS-40B
• Applies whether you’re applying at age 65 or later after delaying both parts
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You’ll likely need two forms:
1. Form CMS-40B – for Part B enrollment
2. Form CMS-L564 – proof of creditable employer coverage
The L564 form is completed by your employer to show you had valid coverage. This helps avoid late enrollment penalties.
⚠️ If you had no creditable coverage, submitting Form L564 will not protect you from a late penalty.
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Use the SSA-44 Form to request a reduction in your Medicare Part B and D premiums due to a life-changing event, such as:
• Retirement
• Loss of a spouse
• Divorce
This is related to IRMAA (Income-Related Monthly Adjustment Amount).
Approval is not guaranteed — SSA must approve your request.
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CMS-18-F-5:
Purpose: Apply for Part A only
CMS-40B:
Purpose: Apply for Part B, or A & B together
CMS-L564:
Purpose: Prove creditable employer coverage (used with delayed Part B)
SSA-44:
Purpose: Request IRMAA premium reduction due to life event