Your
MBI is your 11-character Medicare Beneficiary Identifier - or new Medicare Number (starting April 2018).
From April 2018
through January 2019, the Centers for Medicare &
Medicaid Services (CMS)
sent new Medicare cards with new MBIs to all of the 57.7
million Medicare beneficiaries.
CMS noted that these new Medicare cards "will use a unique,
randomly-assigned [11-character] number called a Medicare Beneficiary
Identifier (MBI), to replace the Social Security-based Health Insurance
Claim Number (HICN) currently used on the Medicare card.”
When you receive your new Medicare card, you will notice that your new MBI
"number" is actually alphanumeric or having both upper-case letters and
numbers (from the sample graphic below you can see the MBI: "1EG4-TE5-MK72").
To
avoid confusion, your MBI will exclude the letters:"S, L, O, I, B, Z"
(since these letters are easily mistaken for numbers).
Your new MBI is unique to you, so you will have a different number than
your spouse and since the MBI is random, there is no
meaning to the number.
CMS began mailing new Medicare cards to Medicare beneficiaries in Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia starting April 2018. Then, in the following months, CMS rolled-out the new Medicare cards across the country and U.S. Territories continuing through April 2019 (but actually completed the mailing
by January 2019).
Here is an example of the
new Medicare card (as of April 2018) with unique and randomly-assigned Medicare Beneficiary Identifier (MBI) (source: CMS)
(Sources include: https://www.cms.gov/newcard,
https://www.medicare.gov/forms-help-and-resources/your-medicare-card.html,
https://www.cms.gov/Medicare/New-Medicare-Card/Partners-and-Employers/Partners-and-employers.html)