Medicare Beneficiary Identifier

October 9, 2017


Medicare has taken a very positive step towards better security by changing patient’s Medicare numbers.  Medicare has traditionally used a patient’s Social Security Number (SSN) followed by a letter to determine the numbers.  Starting April 2018, Medicare will start sending out cards to subscribers with a new, updated number that will be called a Medicare Beneficiary Identifier (MBI).  Medicare has set a deadline of April 2019 to have every number changed over.  The new number will be a combination of numbers and uppercase letters for a combined 11 characters.  They are to be completely randomly generated and each person will get their own separate MBI number.  Here are few of the rules the new MBI will follow:


  • THE MBI’s 2nd, 5th, 8th and 9th characters will be a letter.

  • Characters 1,4,7,10 and 11 will always be a number

  • The 3rd and 6th characters will be a letter or a number

  • Example: 1EG4-TE5-MK73




We are making the necessary preparations at Mobility Medicine for the change over to make our patient’s reimbursement process as smooth as possible.  We wanted everyone to be aware of this change though and please let us know your new number as soon as you get it or at your next appointment.


Please let us know if you have any questions!