---
title: CMS-40B Customer-Assembly Preparation Kit
description: Prepare CMS-40B online and receive an unsigned printed kit for your own final review, hand-signing, assembly, and submission.
seotitle: CMS-40B Customer-Assembly Preparation Kit
seo-description: Prepare CMS-40B online and receive an unsigned printed kit for your own final review, hand-signing, assembly, and submission.
group: resources
indexable: true
llms: false
schema: webpage
og-image: /forms/cms-40b/thumbnail
og-image-alt: Form CMS-40B - Medicare Part B Enrollment generated form preview
published: 2026-07-12
updated: 2026-07-12
tags:
  - medicare
  - medicare part b
  - social security
path: /forms/cms-40b
---
# CMS-40B Customer-Assembly Preparation Kit

Prepare CMS-40B online and receive an unsigned printed kit for your own final review, hand-signing, assembly, and submission.

## How it works
1. **Answer the guided questions and review the prepared form information.** - 
2. **PostalForm prints the official form with signature areas left blank and sends the customer-assembly kit only to your verified address.** - 
3. **After delivery, follow the cover instructions, hand-sign where required, and add every original, certified record, payment, witness, certification, companion form, or other physical item.** - 
4. **Verify the current deadline and destination, then personally complete final submission through the official channel.** -


## Form summary
This workflow helps you prepare a Medicare Part B enrollment application for the applicant to finish and submit. PostalForm prepares the official form and delivers the unsigned preparation kit only to your verified address. PostalForm does not file, serve, or submit it. Hand-sign and date CMS-40B, add a completed employer-signed CMS-L564 or other accepted proof when using a Special Enrollment Period, verify the enrollment window, and submit the final package to the local Social Security office yourself.

## What you need
- Your Medicare number (you must already have Part A)
- Name, mailing address, phone, and email
- Dates of job-based (or volunteer) health coverage since you turned 65, if any
- Form CMS-L564 or other proof of coverage for a Special Enrollment Period
- Signature and date
- Hand-sign the printed form after the preparation kit is delivered
- CMS-L564 or other proof of job-based coverage (for a Special Enrollment Period) (optional) — If you are using the Special Enrollment Period, include Form CMS-L564 (Request for Employment Information) completed by each employer - or other proof such as W-2s, pay stubs, health insurance cards, or benefit statements. Send copies, never originals.
- Extra pages or documentation (optional) (optional) — Attach a separate sheet if you need more room for coverage dates, or the letter or notice that asked you to enroll in Part B (question 4).

## Data collected
- Medicare number (from the red, white, and blue Medicare card)
- Name, mailing address, phone, and email
- Job-based or volunteer health coverage since turning 65, with start and end dates
- Optional Part B coverage start-date choice
- Whether the applicant expects to sign by mark; signature, date, and witness fields remain blank for completion after delivery

## Where it gets mailed
PostalForm mails the unsigned preparation kit only to the customer or authorized signer at the verified delivery address entered during checkout.

Final submission: Hand-sign and date CMS-40B, add a completed employer-signed CMS-L564 or other accepted proof when using a Special Enrollment Period, verify the enrollment window, and submit the final package to the local Social Security office yourself.

## Packet order
- Customer assembly instruction cover (remove and keep before final submission)
- Prepared unsigned form (signature and reserved third-party fields blank)
- Printed reference attachments

## Common mistakes
- Using CMS-40B without having Part A yet - first-time Medicare applications go through Social Security, not this form.
- Missing the 8-month Special Enrollment Period window after job-based coverage or employment ends.
- Counting COBRA or retiree coverage as job-based coverage - they do not qualify you for a Special Enrollment Period.
- Skipping Form CMS-L564 (or other proof of coverage) when enrolling through a Special Enrollment Period.
- Mailing the form to a national Medicare address instead of your local Social Security office.

## Agent summary
Customer-assembly workflow for CMS-40B. It prepares the form and sends an unsigned kit only to the customer. It must never be represented as direct filing, service, or agency submission. Final customer action: Hand-sign and date CMS-40B, add a completed employer-signed CMS-L564 or other accepted proof when using a Special Enrollment Period, verify the enrollment window, and submit the final package to the local Social Security office yourself.

## For assistants
This is a human-only customer-assembly workflow and is not available for automated or machine ordering.

- PostalForm delivers an unsigned preparation kit only to the customer or authorized signer.
- The customer must remove and keep the PostalForm cover, complete every physical signature, enclosure, certification, and final-submission step, and verify the current deadline and destination.

## LLM field schema
```json
[
  {
    "id": "has_part_a",
    "label": "Do you already have Medicare Part A (hospital insurance)?",
    "type": "checkbox",
    "required": true,
    "meta_class": "yes_no",
    "ui_width": null,
    "group_id": "eligibility",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "no_part_a_notice",
    "label": "I understand Form CMS-40B cannot be used without Part A",
    "type": "checkbox",
    "required": true,
    "meta_class": "plain_checkbox",
    "ui_width": null,
    "group_id": "eligibility",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "has_part_a",
      "operator": "equals",
      "value": false
    },
    "compound_subfields": null
  },
  {
    "id": "medicare_number_part1",
    "label": "Medicare number - first 4 characters",
    "type": "text",
    "required": true,
    "meta_class": null,
    "ui_width": "third",
    "group_id": "about-you",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "medicare_number_part2",
    "label": "Middle 3 characters",
    "type": "text",
    "required": true,
    "meta_class": null,
    "ui_width": "third",
    "group_id": "about-you",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "medicare_number_part3",
    "label": "Last 4 characters",
    "type": "text",
    "required": true,
    "meta_class": null,
    "ui_width": "third",
    "group_id": "about-you",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "applicant_name",
    "label": "Your name",
    "type": "compound",
    "required": true,
    "meta_class": null,
    "ui_width": null,
    "group_id": "about-you",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": [
      {
        "id": "first",
        "label": "First name",
        "required": true,
        "uiWidth": "third",
        "sampleValue": "Alex"
      },
      {
        "id": "middle",
        "label": "Middle name",
        "required": false,
        "uiWidth": "third",
        "sampleValue": "J."
      },
      {
        "id": "last",
        "label": "Last name",
        "required": true,
        "uiWidth": "third",
        "sampleValue": "Johnson"
      },
      {
        "id": "suffix",
        "label": "Suffix (Jr., Sr., III)",
        "required": false,
        "uiWidth": "third",
        "sampleValue": ""
      }
    ]
  },
  {
    "id": "mailing_address_street",
    "label": "Mailing address (number and street, P.O. Box, or route)",
    "type": "text",
    "required": true,
    "meta_class": "address",
    "ui_width": "full",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "mailing_address_city",
    "label": "City",
    "type": "text",
    "required": true,
    "meta_class": "city",
    "ui_width": "third",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "mailing_address_state",
    "label": "State",
    "type": "text",
    "required": true,
    "meta_class": "state",
    "ui_width": "third",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "mailing_address_zip",
    "label": "ZIP code",
    "type": "text",
    "required": true,
    "meta_class": "zip",
    "ui_width": "third",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "phone_area",
    "label": "Phone - area code",
    "type": "text",
    "required": false,
    "meta_class": "number",
    "ui_width": "quarter",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "phone_prefix",
    "label": "Phone - next 3 digits",
    "type": "text",
    "required": false,
    "meta_class": "number",
    "ui_width": "quarter",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "phone_line",
    "label": "Phone - last 4 digits",
    "type": "text",
    "required": false,
    "meta_class": "number",
    "ui_width": "quarter",
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "email",
    "label": "Email address (optional)",
    "type": "text",
    "required": false,
    "meta_class": "email",
    "ui_width": null,
    "group_id": "contact",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "employer_coverage_yes",
    "label": "Yes - I (or my spouse) have had job-based coverage",
    "type": "checkbox",
    "required": true,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "employer_coverage_no",
    "label": "No - no job-based coverage since 65",
    "type": "checkbox",
    "required": false,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "job_start_month",
    "label": "Month the job started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "job_start_year",
    "label": "Year the job started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "job_end_month",
    "label": "Month the job ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "job_end_year",
    "label": "Year the job ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "job_not_ended",
    "label": "The job has not ended",
    "type": "checkbox",
    "required": false,
    "meta_class": "plain_checkbox",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "coverage_start_month",
    "label": "Month the health coverage started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "coverage_start_year",
    "label": "Year the health coverage started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "coverage_end_month",
    "label": "Month the health coverage ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "coverage_end_year",
    "label": "Year the health coverage ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "coverage_not_ended",
    "label": "The health coverage has not ended",
    "type": "checkbox",
    "required": false,
    "meta_class": "plain_checkbox",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "employer_coverage_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "volunteer_yes",
    "label": "Yes - I volunteered abroad with health coverage",
    "type": "checkbox",
    "required": true,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "volunteer_no",
    "label": "No",
    "type": "checkbox",
    "required": false,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "volunteer_start_month",
    "label": "Month the volunteer service started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "volunteer_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "volunteer_start_year",
    "label": "Year the volunteer service started",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "volunteer_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "volunteer_end_month",
    "label": "Month the volunteer service ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "volunteer_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "volunteer_end_year",
    "label": "Year the volunteer service ended",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "volunteer_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "volunteer_not_ended",
    "label": "The volunteer service has not ended",
    "type": "checkbox",
    "required": false,
    "meta_class": "plain_checkbox",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "volunteer_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "asked_to_enroll_yes",
    "label": "Yes - someone asked or required me to enroll",
    "type": "checkbox",
    "required": true,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "asked_to_enroll_no",
    "label": "No",
    "type": "checkbox",
    "required": false,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "asked_to_enroll_explanation",
    "label": "Explain who asked you to enroll, and why",
    "type": "textarea",
    "required": true,
    "meta_class": null,
    "ui_width": null,
    "group_id": "job-coverage",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "asked_to_enroll_yes",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "still_covered_now",
    "label": "Are you still covered by that job-based plan - or did it end less than a month ago?",
    "type": "checkbox",
    "required": true,
    "meta_class": "yes_no",
    "ui_width": null,
    "group_id": "start-date",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "start_first_month",
    "label": "The first day of the month I enroll",
    "type": "checkbox",
    "required": true,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "start-date",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "still_covered_now",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "start_later_month",
    "label": "The first day of a month up to 3 months after I enroll",
    "type": "checkbox",
    "required": false,
    "meta_class": "radio",
    "ui_width": null,
    "group_id": "start-date",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "still_covered_now",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "chosen_start_month",
    "label": "Month you want Part B to start",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "start-date",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "start_later_month",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "chosen_start_year",
    "label": "Year you want Part B to start",
    "type": "text",
    "required": true,
    "meta_class": "date",
    "ui_width": "quarter",
    "group_id": "start-date",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "start_later_month",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "applicant_signature",
    "label": "Your signature",
    "type": "signature",
    "required": true,
    "meta_class": null,
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "date_signed_month",
    "label": "Date signed",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "date_signed_day",
    "label": "Day",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "date_signed_year",
    "label": "Year",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "signed_by_mark",
    "label": "Will the applicant sign with an X mark instead of a written signature?",
    "type": "checkbox",
    "required": true,
    "meta_class": "yes_no",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  },
  {
    "id": "witness_name",
    "label": "Witness full name (first and last)",
    "type": "text",
    "required": false,
    "meta_class": "name",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "signed_by_mark",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "witness_signature",
    "label": "Witness signature",
    "type": "signature",
    "required": true,
    "meta_class": null,
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "signed_by_mark",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "witness_date_signed_month",
    "label": "Witness date signed",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "signed_by_mark",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "witness_date_signed_day",
    "label": "Day",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "signed_by_mark",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "witness_date_signed_year",
    "label": "Year",
    "type": "text",
    "required": false,
    "meta_class": "date",
    "ui_width": null,
    "group_id": "signature",
    "choice_group": null,
    "choice_label": null,
    "visibility": {
      "fieldId": "signed_by_mark",
      "operator": "truthy"
    },
    "compound_subfields": null
  },
  {
    "id": "mailing_ack",
    "label": "I will mail this to my local Social Security office",
    "type": "checkbox",
    "required": true,
    "meta_class": "plain_checkbox",
    "ui_width": null,
    "group_id": "mailing",
    "choice_group": null,
    "choice_label": null,
    "visibility": null,
    "compound_subfields": null
  }
]
```

## Sources
- [CMS - Form CMS-40B page](https://www.cms.gov/medicare/cms-forms/cms-forms/cms-forms-items/cms017339)
- [SSA FAQ - How do I sign up for Part B if I already have Part A?](https://www.ssa.gov/faqs/en/questions/KA-02131.html)
- [Medicare.gov - Ready to sign up for Part A and Part B](https://www.medicare.gov/basics/get-started-with-medicare/sign-up/ready-to-sign-up-for-part-a-part-b)
- [SSA blog - Sign up for Medicare Part B online, by fax, or by mail](https://blog.ssa.gov/sign-up-for-medicare-part-b-online-by-fax-or-by-mail/)
- [Official instructions](https://www.ssa.gov/medicare/sign-up/part-b-only)
- [Official PDF](https://www.cms.gov/medicare/cms-forms/cms-forms/downloads/cms40b-e.pdf)

## Last verified
2026-07-12


## FAQs
- **Where do I mail Form CMS-40B?** To your local Social Security office - there is no national address. Find yours with the Social Security office locator at secure.ssa.gov/ICON or call 1-800-772-1213. You can also fax the signed form to 1-833-914-2016.
- **Can I sign up for Medicare Part B online instead of mailing this form?** Usually, yes. If you already have Part A, you can apply at ssa.gov/medicare/sign-up and upload your proof of coverage. Mailing the paper CMS-40B is right for people who prefer paper or cannot use the online application.
- **Do I also need Form CMS-L564?** Only if you are enrolling through a Special Enrollment Period based on job coverage. Each employer whose coverage you are counting should verify it on Form CMS-L564 - or you can include other proof, like W-2s, pay stubs, health insurance cards, or benefit statements.
- **When will my Part B coverage start?** Generally the first day of the month after Social Security processes your enrollment. If you are still covered by a job-based plan (or within the first full month after it ends), the form lets you choose a start month up to 3 months after you enroll.
- **What is the Part B late enrollment penalty?** Usually an extra 10% of the standard premium for each full 12-month period you could have had Part B but did not sign up - and it lasts for as long as you have Part B. Enrolling during your Initial or Special Enrollment Period avoids it.
- **Does COBRA or retiree coverage count for the Special Enrollment Period?** No. The Special Enrollment Period is based on current employment. Your 8-month window starts when the employment or the active-employment coverage ends, whichever comes first - COBRA and retiree plans do not extend it.


## Related
- [Form CMS-L564 - Medicare Employment Verification](/forms/cms-l564)
- [Form CMS-1763 — Medicare Part A/B Termination Request](/forms/cms-1763)
- [CMS-1490S](/forms/cms-1490s)
- [Form SSA-44 — Medicare IRMAA Reduction Request (Life-Changing Event)](/forms/ssa-44)
- [Form SS-5 — Application for a Social Security Card](/forms/ss-5)
- [SSA-1696 — Appointment of Representative (Social Security)](/forms/ssa-1696)