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Medicare Beneficiary Identifier (MBI) - JE Part B

Medicare Beneficiary Identifier (MBI)

The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) requires CMS to remove Social Security Numbers (SSNs) from all Medicare cards by April 2019. A new randomly generated Medicare Beneficiary Identifier (MBI) will replace the SSN-based Health Insurance Claim Number on new Medicare cards for transactions like billing, eligibility status, and claim status. Prepare for this change by visiting the new overview and provider webpages.

Implementation: January 1, 2020

Regardless of date of service, providers must use the MBI for all Medicare transactions.

  • Use MBI as soon as your beneficiary receive their new card
  • MBI is effective once new card is received
  • New Medicare beneficiaries will only be assigned an MBI

Claims not submitted with the MBI as of January 1, 2020 will be rejected and will need to be resubmitted with a valid MBI.

A beneficiary's MBI may change if their card was lost or stolen. In these instances, the provider will need to obtain the new MBI from the beneficiary or through the Noridian Medicare Portal.

Fee-for-Service Claim Exceptions

  • Appeals - Submit either HICN or MBI for claims appeals and related forms
  • Claim status query - Submit HICN or MBI to check status of a claim (276 transactions) if earliest date of service on the claim is before January 1, 2020. If checking status of a claim with a date of service on/after January 1, 2020, MBI must be used

MBI Format

  • MBI is randomly generated
  • MBI consists of 11 non-intelligent characters (number and upper-case letters) and have no special meaning
    • Numbers 1-9 and all letters from A-Z, except for S, L, O, I, B, and Z
  • MBI Example: 1EG4-TE5-MK73
Position 1 2 3 4 5 6 7 8 9 10 11
Type C A AN N A AN N A A N N


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

MBIs will fit on claim forms same as a HICN. No spaces or dashes.

Each Medicare beneficiary will receive an MBI.

How to Prepare

  1. Beneficiary Intake
    • At time of service, ask beneficiaries if he/she has a new Medicare card
    • Verify beneficiary's address
      • He/she won't get a new card if their address is incorrect
      • If address on file is different than address in eligibility response, ask your beneficiary to contact Social Security Administration (SSA) at 1-800-772-1213 to update their records

Eligibility Transaction Responses

Providers can use the Noridian Medicare Portal (NMP) as a Look-up Tool for MBIs. To receive the MBI from NMP, the beneficiary must give a provider his/her HICN plus verify their first name, last name, and date of birth. Beneficiaries can also log into to obtain their MBI.


Last Updated Wed, 20 Apr 2022 17:26:21 +0000

The below are topic specific articles which have been published to "Latest Updates" and sent out in Noridian emails within the past two years. Exclusions to this include time sensitive related announcements such as: Noridian and CMS educational events, Ask-the-Contractor Teleconferences and claims processing downtime.

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