Around 2.8 million new Medicare cards have been mailed to beneficiaries with new Medicare Beneficiary Identifier (MBI) numbers due to fraud. Medicare is sending these new cards with a letter explaining why new numbers were issued.
Beneficiaries who receive a new card and are unsure of its legitimacy can call 800-Medicare or OSHIIP at 800-686-1526 for assistance. These new cards are NOT plastic. They are the standard paper red/white/blue card.
Before you worry — this update does not mean your Medicare coverage is changing.
What Is an MBI?
Your Medicare Beneficiary Identifier (MBI) is the number printed on your red, white, and blue Medicare card. Doctors, hospitals, pharmacies, and insurance companies use this number to process your claims. In 2026, some beneficiaries will receive a new card with a different MBI.
Why Is CMS Reissuing Some MBIs?
CMS periodically updates and reassigns Medicare numbers for administrative and security purposes.
This is a routine system update and does NOT affect your:
- Medicare benefits
- Medicare Advantage plan
- Prescription drug coverage
- Medicare Supplement plan
- Monthly premium
Only the number itself is changing.
What Should You Expect?
If you are one of the beneficiaries impacted:
- You will receive a new Medicare card in the mail in March 2026.
- Your new MBI becomes active on April 14, 2026.
- Your coverage remains the same.
- You should begin using your new card once it becomes effective.
After receiving your new card:
- Destroy your old Medicare card.
- Update your doctors, pharmacy, and any medical providers if needed.
- Keep the new card in a safe place.
Important Reminder About Scams: Whenever Medicare numbers change, scammers try to take advantage of the confusion.
REMEMBER…
- Medicare will never call you asking for payment to issue a new card.
- You do not need to pay to receive your updated Medicare card.
- If someone calls asking for personal information related to this change, hang up.
If you receive something in the mail and are unsure whether it is legitimate, contact a trusted source before responding.