If you’ve been enrolled in Medicare for some time or are reviewing older documents, you might notice a Medicare number ending with a letter, such as “A” or “B1.” These letters were part of the Health Insurance Claim Number (HICN) system, which was replaced by the Medicare Beneficiary Identifier (MBI) system in 2020. The MBI is a randomly generated 11-character alphanumeric code that does not include any personal information.
Transition from HICN to MBI
The shift from HICN to MBI was implemented to enhance the security and privacy of Medicare beneficiaries. Unlike HICNs, which were based on Social Security Numbers (SSNs) and included suffix letters indicating eligibility, MBIs are randomly generated and do not convey any personal information.
Understanding the Old HICN Suffix Letters
While MBIs are now the standard, understanding the old HICN suffix letters can be helpful when reviewing historical documents. Here are some common suffixes and their meanings:
A: Primary claimant who has paid into the Medicare system.
B: Spouse of the primary claimant.
C: Child of the primary claimant.
D: Widow or widower of the primary claimant.
E: Parent of the primary claimant.
F: Other family members, such as step-parents or adoptive parents.
H: Disabled claimant or family member of a disabled claimant.
J/K: Special beneficiaries with specific eligibility criteria.
M: Individuals enrolled in Medicare Part B but not eligible for Part A.
T: Individuals eligible for Medicare due to specific conditions, such as chronic kidney disease.
W: Disabled widow or widower.
Please note that these suffixes are no longer used in the current MBI system.
The Current MBI Format
The MBI is a unique 11-character alphanumeric code assigned to each Medicare beneficiary. It does not include any personal information and is designed to protect your identity. An example of an MBI is: 1EG4-TE5-MK73. The format is as follows:
Characters 1, 4, 7, 10, and 11 are numbers.
Characters 2, 5, 8, and 9 are letters.
Characters 3 and 6 can be either letters or numbers.
The letters S, L, O, I, B, and Z are excluded to avoid confusion with similar-looking numbers.
Key Takeaways
The letters at the end of your old Medicare number were part of the HICN system and indicated your eligibility status.
As of 2020, Medicare uses the MBI system, which does not include any personal information or eligibility indicators.
Understanding the old suffixes can be helpful when reviewing historical documents, but they are no longer used in current Medicare identification.