What Your Medicare Number Is and Where to Find It

Your Medicare Number Is Your Unique Identifier in the System

Your Medicare number is a 10-digit code that identifies you in Medicare's records. It appears on your Medicare card and stays with you for life. You need this number every time you see a doctor, fill a prescription, or file a claim — it tells the system which account the bill belongs to.

The number itself is not your Social Security number, though it used to be based on it. In 2015, Medicare switched to random numbers for new beneficiaries. If you enrolled before 2015, your Medicare number may still contain your Social Security number, but the format is the same: 10 digits printed on your card.

Your Medicare number is different from your Health Insurance Claim Number (HICN), which was the old name for the same thing. You may still see HICN mentioned in older documents or on some websites, but it refers to the same 10-digit code on your current card.

Key Takeaways

Your Medicare number is a 10-digit code on your Medicare card that identifies you in the system and is required at every doctor visit and pharmacy.
Medicare numbers issued before 2015 were based on Social Security numbers; newer numbers are random and do not contain personal information.
You can find your Medicare number on your physical card, in your online Medicare account, or by calling 1-800-MEDICARE.
Your Medicare number stays the same throughout your life unless you report a change to Medicare directly.
You should protect your Medicare number the same way you protect your Social Security number, as it can be used to access your health records.

Where Your Medicare Number Appears

Your Medicare number is printed on the front of your Medicare card in large type. The card also shows your name, the date coverage began, and which parts of Medicare you have (Part A, Part B, Part D). If you have a physical card, the number is straightforward to locate — it is the longest string of numbers on the front.

If you do not have your card in front of you, you can view your Medicare number in your online Medicare account at Medicare.gov. Log in with your username and password, go to "My Health Information," and your number will appear there. You do not need to call or visit an office to retrieve it.

You can also call 1-800-MEDICARE (1-800-633-4227) and speak to a representative who will confirm your identity and read your Medicare number to you over the phone. This line is open 24 hours a day, 7 days a week.

What Your Medicare Number Contains

If you enrolled in Medicare before 2015, your 10-digit number is structured as follows: the first five digits are based on your Social Security number, the next two digits are a group code, and the last three digits are a claim number. This structure is why older Medicare numbers can reveal personal information.

If you enrolled in 2015 or later, your Medicare number is completely random. It does not contain your Social Security number or any other identifying information. Both old and new numbers work the same way in the Medicare system — the format changed only to protect privacy for new beneficiaries.

Your Medicare number is separate from your Member ID if you have a Medicare Advantage plan or other supplemental coverage. Your supplemental plan will issue its own ID number, and you may need both numbers when you see a doctor or fill a prescription.

When You Need to Provide Your Medicare Number

You will need your Medicare number at the doctor's office, hospital, or urgent care clinic before your first visit. The staff will ask for it so they can bill Medicare for your care. Bring your Medicare card with you to every appointment, or have the number written down if you do not have the card.

Pharmacies also ask for your Medicare number when you fill a prescription covered by Medicare Part D. If you do not have the number memorized, the pharmacy can look it up using your name and date of birth, but having it ready speeds up the process.

You will also need your Medicare number if you file a claim yourself, request records from Medicare, or contact Medicare customer service about your account. Keep a copy of your number in a safe place — not in your wallet with your card, but somewhere you can find it quickly if needed.

Protecting Your Medicare Number

Your Medicare number should be treated as carefully as your Social Security number. Anyone with your Medicare number can potentially access your health records or file claims in your name. Do not share it over email, text, or phone unless you initiated the contact and you are certain you are speaking to Medicare or your doctor's office.

Medicare and legitimate healthcare providers will never call you out of the blue asking for your Medicare number. If someone calls claiming to be from Medicare and asks for your number, hang up and call 1-800-MEDICARE yourself to verify whether they contacted you legitimately.

If you believe your Medicare number has been compromised or used fraudulently, contact Medicare when ready at 1-800-MEDICARE. You can also report suspected fraud to the Office of Inspector General at HHS.gov/oig or by calling 1-800-HHS-TIPS.

What Happens If You Lose Your Card

If your Medicare card is lost or damaged, you can order a replacement through your online Medicare account or by calling 1-800-MEDICARE. A new card will arrive by mail within 7 to 10 business days. Your Medicare number does not change — the new card will have the same number printed on it.

While you wait for your replacement card, you can still see doctors and fill prescriptions. Provide your Medicare number verbally or write it down if you have it memorized. If you do not know your number, the doctor's office or pharmacy can look it up using your name and date of birth.

Frequently Asked Questions

Does my Medicare number change if I move to a different state?

No. Your Medicare number stays the same no matter where you live. You do not need to notify Medicare of a move for your number to remain valid. If you change your address, update it in your Medicare account or call 1-800-MEDICARE so they have your correct mailing address.

Can I use my spouse's Medicare number if I do not have my card?

No. Each person has their own unique Medicare number, and using someone else's number will cause billing and record-keeping problems. Always provide your own number or allow the office to look it up using your name and date of birth.

What if my Medicare number has a letter at the end?

Some older cards included a letter suffix (A, B, or D) to indicate a family member's relationship to the primary account holder. This letter is no longer used on new cards. If your card has a letter, include it when you provide your number to a doctor or pharmacy, but most modern systems will recognize the 10-digit number alone.

Is my Medicare number the same as my claim number?

No. Your Medicare number is your main identifier. Your claim number is a separate reference number assigned to individual claims you file. When you see a bill or explanation of benefits, it will reference both your Medicare number and a claim number for that specific service.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.