What documents do you need to sign up for Medicare?
Most people need proof of age, proof of citizenship or legal residency, and their Social Security number.
If you’re signing up for Part B after employer coverage, you may also need CMS forms like CMS-40B and CMS-L564.
To sign up for Medicare, you’ll typically need proof of identity and age (such as a birth certificate or passport), your Social Security number, and proof of U.S. citizenship or lawful residency.
If you’re already receiving Social Security benefits, much of this may be on file. If you’re enrolling after 65 due to employer coverage, you may also need employer forms like CMS-L564 to prove you had creditable health insurance and avoid late-enrollment penalties.
For most people, you can sign up online at SSA.gov in about 10 minutes, or visit your local Social Security office if you need in-person help. Preparing your paperwork ahead of time means no delays in coverage and no missed deadlines.
If you’re not sure what to bring or how to start, GenerationHealth can guide you through every step of the Medicare enrollment process.
✅📄 What Documents Do You Need to Sign Up for Medicare? (Simple Checklist)
If you’re feeling stressed and thinking, “what documents do you need to sign up for Medicare” — you’re not alone. Medicare enrollment sounds simple, but the paperwork can feel confusing.
Here’s the good news: most people don’t need a huge stack of papers. In many cases, Social Security already has your info on file—especially if you’re already getting Social Security benefits.
This guide explains what documents do you need to sign up for Medicare in plain English, plus what to do if you’re turning 65, losing employer coverage, or enrolling late.
Helpful official sites to keep open in another tab: Medicare.gov and SSA.gov. Medicare
Most people start here to compare options privately — no contact info, no obligation, and no enrollment required.
✅📄 What documents do you need to sign up for Medicare? (The core checklist)
Here’s the “most common” document checklist. You may not need every item, but these are the usual ones people are asked for:
Your Social Security number
Usually your Social Security card, or any official proof of your SSN.
Proof of age
Common examples: birth certificate, U.S. passport, or other official record.
Proof of U.S. citizenship or legal residency (if needed)
Examples: U.S. passport, Certificate of Citizenship, or permanent resident card (green card).
Medicare generally requires lawful permanent residents to have lived in the U.S. continuously for a certain time before qualifying. (If this is you, it’s worth double-checking your situation with Social Security.) Social Security
Work history / tax records (sometimes requested)
Examples: W-2s, self-employment tax records, or military discharge papers (if relevant).
This can help confirm eligibility for premium-free Part A or other details. Healthgrades
If you’re thinking “what documents do you need to sign up for Medicare”, start with #1–#3. Most people are covered with those.
Penalty percentages (what happens if you enroll late)
Penalties are a big reason people want to enroll correctly the first time.
Part B late enrollment penalty (the big one)
If you don’t sign up for Part B when you’re first eligible (and you don’t qualify for a Special Enrollment Period), Medicare can increase your Part B premium by 10% for each full 12-month period you could have had Part B but didn’t. Medicare
Part D late enrollment penalty (prescriptions)
If you go without Part D (or other “creditable” drug coverage) when you were eligible, Medicare generally charges 1% per month (based on the national base beneficiary premium) for the number of full months you were uncovered. Medicare
Plain-English tip: If you’re delaying Part B because you have active employer coverage, keep proof of that coverage. That paperwork is what protects you from the penalty later. Medicare
This is where most people begin when they want to compare options quietly — no contact info, no obligation, and no enrollment required.
Comparison tables (documents by situation)
Table 1: Documents you’ll likely need (most common scenarios)
| Situation | What you’re doing | Documents to prepare |
|---|---|---|
| Turning 65 & enrolling on time | Signing up for Parts A & B | Proof of age, SSN, proof of citizenship/residency (if needed) |
| Already getting Social Security | Often auto-enrolled in Part A (and sometimes Part B) | Usually minimal—still keep proof of age & SSN handy |
| Losing employer coverage | Adding Part B after delaying | Employer coverage proof + required CMS forms |
| Missed your window | Trying to enroll later | Forms + documents depend on reason and enrollment period |
Table 2: CMS forms (when they show up)
| Form | When it’s used | Why it matters |
|---|---|---|
| CMS-40B | Signing up for Part B (often after delaying) | Tells SSA you want Part B Medicare |
| CMS-L564 | When you had employer coverage and delayed Part B | Employer confirms coverage dates (helps avoid penalties) Medicare |
| CMS-10797 | “Exceptional conditions” Special Enrollment Period (SEP) | Used in certain special situations Medicare |
Here’s what we see (real-world enrollment problems)
As a broker, here are the most common “paperwork” issues we see:
People enroll in Part A but forget Part B, then get stuck waiting for the next allowed enrollment window.
People don’t get the employer form filled out (CMS-L564), so their Part B gets delayed or triggers a penalty risk. Medicare
People assume “I’m covered” but their coverage wasn’t considered creditable, which can cause a Part D penalty. Medicare
People don’t keep copies (fax confirmations, mailed receipts, screenshots).
If you’re stuck, the fastest “how-to” walkthrough is: bold link generationhealth.me/how-to-sign-up-for-medicare-parts-a-and-b/
Explicit explanations (plain English, no jargon)
When Medicare (and Social Security) ask for documents, they’re basically checking 3 things:
Who you are (identity + Social Security number)
How old you are (Medicare age eligibility)
Whether you qualify (citizenship/residency + work history rules)
That’s it.
So when someone asks, “what documents do you need to sign up for Medicare”, the simplest answer is:
“Something that proves your age, your SSN, and your legal status in the U.S.”
Enrollment timelines (so you don’t miss your window)
Here are the main timelines to know:
Initial Enrollment Period (IEP)
This is the window around when you turn 65. It’s the easiest time to enroll.
Special Enrollment Period (SEP)
If you had active employer coverage and delayed Part B, you may be able to enroll without penalties—but you must prove you had that coverage (this is where CMS-L564 usually comes in). Medicare
General Enrollment Period (GEP)
If you missed your chance and don’t qualify for an SEP, you may have to use the GEP (and penalties can apply). Medicare
If you’re approaching 65, this page helps you plan your next step: bold link generationhealth.me/turning-65-medicare-enrollment-n-c
(“Illustrative estimates based on CMS trends”)
FAQ Information
Q1: What documents do you need to sign up for Medicare if you’re turning 65?
Most people need proof of age (like a birth certificate or passport), their Social Security number, and proof of citizenship/legal residency if Social Security needs it. Social Security
Q2: Do I need documents if I’m already receiving Social Security?
Often, less paperwork is needed because much is already on file—but keep proof of age and SSN available in case you’re asked.
Q3: What if I delayed Part B because I had employer insurance?
You’ll usually need proof of your employer coverage dates, often through CMS-L564, and you may also need CMS-40B to enroll in Part B. Medicare
Q4: What if I enroll late—how big are the penalties?
Part B can increase by 10% for each full 12-month period you delayed without qualifying coverage. Part D is typically 1% per uncovered month, based on the national base beneficiary premium. Medicare
Q5: Where do I officially enroll?
You can enroll through Social Security at ssa.gov. Medicare provides guidance at medicare.gov. Social Security
1) Do I need my birth certificate to enroll?
You don’t always need the original certificate. A valid U.S. passport or other official proof of age/citizenship works. Bring one government-issued proof of identity plus one proof of age.
2) What if I’m still working at 65?
You can delay Part B if you have creditable employer coverage. Keep Form CMS-L564 and a letter from HR showing your continuous coverage and the end date—you’ll need both to avoid penalties when you retire.
3) I’m on COBRA—does that count as creditable for Part B?
COBRA does not protect you from the Part B late-enrollment penalty. If you’re 65+, enroll in Part B when first eligible unless you’re covered by active employer insurance.
4) Enrolling online vs. in person—what should I prepare?
For SSA.gov: have your driver’s license, Social Security number, and prior coverage details handy. For in person: bring hard copies (or certified copies) of the same, plus any employer forms.
5) Name or address mismatch?
Bring documentation that connects prior/maiden names (marriage certificate, court order). Mismatches can slow verification.
6) What if I can’t find my documents?
You can request replacements (e.g., birth certificate from vital records, Social Security card from SSA). Meanwhile, bring any alternative proofs you do have to keep things moving.
This is where most people begin when they want to compare options quietly
— no contact info, no obligation, and no enrollment required.
🪪 Do I need proof of citizenship to enroll in Medicare?
Yes. Medicare requires proof of U.S. citizenship or lawful permanent residency, such as a passport or green card. These documents are reviewed during enrollment to confirm eligibility, as outlined in official guidance from Medicare.gov.
💼 What documents are needed if I’m still working at 65?
If you’re still working, you may need employer coverage verification, such as a completed CMS-L564 form. This confirms active group health coverage and helps you qualify for a Special Enrollment Period, preventing Part B penalties per Medicare.gov rules.
🖥️ What documents do I need to apply for Medicare online?
Applying online usually requires your Social Security number, personal identification, and basic employment history. Having these documents ready speeds up the application and reduces errors, especially when enrolling through official Medicare and Social Security systems.
⏱️ What happens if I don’t have all my Medicare documents ready?
Missing documents can delay Medicare enrollment or coverage start dates. In some cases, you may need to submit additional verification later. Medicare.gov recommends gathering paperwork early to avoid interruptions or late-enrollment penalties.
📝 How do I sign up for Medicare for the first time?
You can sign up for Medicare during your Initial Enrollment Period, which starts 3 months before turning 65. Enrollment is completed through Social Security, either online, by phone, or in person. Official guidance and steps are confirmed by Medicare.gov.
This is where most people begin when they want to compare options quietly
— no contact info, no obligation, and no enrollment required.
In our experience (the fastest way to avoid delays)
Here’s the “broker-style” checklist we suggest before you hit submit:
Take clear photos/scans of your key documents
Write down the exact date your employer coverage ends
Ask HR for the CMS-L564 form early (don’t wait until the last week) Medicare
Keep a folder called “Medicare Enrollment” on your phone or computer
Save proof you sent forms (fax confirmation, certified mail receipt, screenshots)
If you want a simple plan comparison after you’re enrolled, start here: bold link generationhealth.me//free-medicare-quotes-online/
What most sites get wrong
A lot of websites make Medicare sound like “one signup.” In real life, Medicare enrollment depends on:
Whether you’re enrolling in Part A, Part B, or both
Whether you had employer coverage (and whether it was the right type)
Whether you need CMS forms (especially when adding Part B later) Medicare
The other mistake: many sites don’t clearly explain that penalties can follow you for as long as you have coverage (especially Part B). Medicare+1
Common outcomes (what happens after you submit)
Most people fall into one of these outcomes:
Approved quickly (no extra documents needed)
SSA asks for 1–2 missing items (most often proof of employer coverage dates)
Enrollment delayed because forms weren’t filled out correctly (CMS-L564 is a common culprit) Medicare
Penalty applies if you didn’t have a valid enrollment period
If you want help sorting options once you’re enrolled, go here: bold link generationhealth.me/Medicare-quote
👥 Who this is for (so you know you’re in the right place)
This post is for you if:
You’re turning 65 and want a simple document checklist
You’re leaving employer coverage and need Part B
You’re worried you missed a deadline and want to avoid penalties
You keep asking, “what documents do you need to sign up for Medicare” and want a straight answer
Explore More Medicare Enrollment Resources
If you’re preparing to enroll in Medicare or want to avoid common mistakes, these detailed guides will help you understand every step of the process:
When to Apply for Medicare: Key Enrollment Periods Explained
Learn the difference between the Initial, Special, and General Enrollment Periods and the exact timeline for enrolling.
👉 https://generationhealth.me/when-to-apply-for-medicare-key-enrollment-periods-explained/When to Apply for Medicare – Avoid Penalties and Gaps in Coverage
See how missing your enrollment window can lead to lifelong penalties and how to avoid costly coverage gaps.
👉 https://generationhealth.me/when-to-apply-for-medicare-avoid-penalties-and-gaps-in-coverage/What Documents Do You Need to Sign Up for Medicare?
A complete checklist of documents required for Medicare Parts A and B, including SEP forms, proof of identity, and citizenship paperwork.
👉 https://generationhealth.me/what-documents-do-you-need-to-sign-up-for-medicare/Do You Need Medicare if You Still Work?
Find out whether employer coverage allows you to delay Medicare without penalties and when a Special Enrollment Period applies.
👉 https://generationhealth.me/do-you-need-medicare-if-you-still-work/How to Correct a Medicare Application
Instructions for fixing mistakes on your Medicare application and when to contact Social Security or your Medicare plan.
👉 https://generationhealth.me/how-to-correct-a-medicare-application/
Identity + work history checks: When you apply for Medicare online, Social Security may verify your identity and work history electronically—but if there are gaps or name changes, you may be asked to upload or mail supporting documents like a birth certificate, marriage certificate, or W-2s to confirm your eligibility and work credits.
Employer coverage proof deadline: If you’re signing up for Medicare after age 65 because you had employer coverage, Social Security typically requires form CMS-L564 (Request for Employment Information) to prove you had creditable coverage. Without that form, you could be treated as a late enrollee and be subject to permanent late-enrollment penalties on your Part B premium.
🧑💼 About the Author
Rob Simm is a licensed independent Medicare agent and the founder of GenerationHealth.me — a health insurance brokerage dedicated to helping seniors and families make confident, informed coverage decisions. With years of experience guiding clients through Medicare, ACA Marketplace, and supplemental plans, Rob simplifies complex enrollment steps into easy-to-follow solutions that protect both health and budget.
When he’s not meeting with clients or hosting local “Birthday Rule” seminars in North Carolina and Virginia, Rob enjoys community events and helping residents navigate their health coverage options online through GenerationHealth.ai — his growing AI-powered quoting and education platform.
📞 Contact: (828)761-3324
Email:[email protected]
⚖️ Compliance & Trust Disclaimer
Information provided on this page is for educational purposes only and should not be considered legal or financial advice.
Plan availability, premiums, and benefits may vary by location and carrier.
Always verify specific details with a licensed insurance professional or directly with Medicare.gov before enrolling.
GenerationHealth.me and Robert Simm are independent agents and not affiliated with or endorsed by the U.S. government or the federal Medicare program.