By Dr. Richard E. Wild, M.D., FACEP

Medicare is taking steps to remove Social Security numbers from Medicare cards. Through this initiative the Centers for Medicare & Medicaid Services (CMS) will prevent fraud, fight identity theft and protect essential program funding and the private healthcare and financial information of our Medicare beneficiaries.

CMS will issue new Medicare cards with a new unique, randomly-assigned number called a Medicare Beneficiary Identifier (MBI) to replace the existing Social Security-based Health Insurance Claim Number (HICN) both on the cards and in various CMS systems we use now. We’ll start mailing new cards to people with Medicare benefits in April 2018. All Medicare cards will be replaced by April 2019.

CMS is committed to helping providers by giving them the tools they need. We want to make this process as easy as possible for you, your patients, and your staff. Based on feedback from healthcare providers, practice managers and other stakeholders, CMS is developing capabilities where doctors and other healthcare providers will be able to look up the new MBI through a secure tool at the point of service. To make this change easier for you and your business operations, there is a 21-month transition period where all healthcare providers will be able to use either the MBI or the HICN for billing purposes.

Even though, your systems will need the capability to accept the new MBI format by April 2018, you can continue to bill and file healthcare claims using a patient’s HICN during the transition period. We encourage you to work with your billing vendor to make sure that your system will be updated to reflect these changes as well.

Beginning in April 2018, Medicare patients will come to your office with new cards in hand. We’re committed to giving you information you need to help your office get ready for new Medicare cards and MBIs.

Here are 5 steps you can take today to help your office or healthcare facility get ready:

  1. Go to our provider website and sign-up for the weekly MLN Connects®
  2. Attend our quarterly calls to get more information. We’ll let you know when calls are scheduled in the MLN Connects newsletter.
  3. Verify all of your Medicare patients’ addresses. If the addresses you have on file are different than the Medicare address you get on electronic eligibility transactions, ask your patients to contact Social Security and update their Medicare records.
  4. Work with us to help your Medicare patients adjust to their new Medicare card. When available later this fall, you can display helpful information about the new Medicare cards. Hang posters about the change in your offices to help us spread the word.
  5. Test your system changes and work with your billing office staff to be sure your office is ready to use the new MBI format.

We’ll keep working closely with you to answer your questions and hear your concerns. To learn more, visit:


Wild_Richard_01.jpg US flag portrait head shot, CO photo 9.11.15Dr. Richard E. Wild, M.D., FACEP, is Chief Medical Officer, Centers for Medicare and Medicaid Region IV (AL, Fl, GA, KY, MS, NC, SC, TN)







Understanding the Medicare Beneficiary Identifier (MBI) Format

How many characters will the MBI have?
The MBI has 11 characters, like the Health Insurance Claim Number (HICN), which can have up to 11.

Will the MBI’s characters have any meaning?
Each MBI is randomly generated. This makes MBIs different than HICNs, which are based on the Social Security Numbers (SSNs) of people with Medicare. The MBI’s characters are “non-intelligent” so they don’t have any hidden or special meaning.

What kinds of characters will be used in the MBI?
MBIs are numbers and upper-case letters. We’ll use numbers 0-9 and all letters from A to Z, except for S, L, O, I, B, and Z. This will help the characters be easier to read.

How will the MBI look on the new card?
The MBI will contain letters and numbers.  Here’s an example: 1EG4-TE5-MK73

  • The MBI’s 2nd, 5th, 8th, and 9th characters will always be a
  • Characters 1, 4, 7, 10, and 11 will always be a
  • The 3rd and 6th characters will be a letter or a
  • The dashes aren’t used as part of the MBI. They won’t be entered into computer systems or used in file

MBI Format

Pos. 1 2 3 4 5 6 7 8 9 10 11
Type C A AN N A AN N A A N N

Where will the MBI’s characters go?

C    – Numeric 1 thru 9         N    – Numeric 0 thru 9       AN – Either A or N
A    – Alphabetic Character (A…Z); Excluding (S, L, O, I, B, Z)

Position 1 – numeric values 1 thru 9
Position 2 – alphabetic values A thru Z (minus S, L, O, I, B, Z)
Position 3 – alpha-numeric values 0 thru 9 and A thru Z (minus S, L, O, I, B, Z)
Position 4 – numeric values 0 thru 9
Position 5 – alphabetic values A thru Z (minus S, L, O, I, B, Z)
Position 6 – alpha-numeric values 0 thru 9 and A thru Z (minus S, L, O, I, B, Z)
Position 7 – numeric values 0 thru 9
Position 8 – alphabetic values A thru Z (minus S, L, O, I, B, Z)
Position 9 – alphabetic values A thru Z (minus S, L, O, I, B, Z)
Position 10 – numeric values 0 thru 9
Position 11 – numeric values 0 thru 9

How will the MBI fit on forms?
MBIs will fit on forms the same way HICNs do. You don’t need spaces for dashes.

Who will get a new MBI?
Each person with Medicare will get their own randomly-generated MBI. Spouses or dependents who may have had similar HICNs will each get their own different MBI.