Medicare Beneficiary Identifier

MBI

member

Updated 5/15/2026

Definition

An 11-character alphanumeric identifier replacing the Social Security-based HICN on Medicare claims and eligibility files as of 2018. Stored in member enrollment and claims systems, the MBI is required on all CMS transactions including 837 claim submissions, 835 remittance files, and eligibility verification responses.

Standard Abbreviation

MBI

Database Usage

-- Example column naming
CREATE TABLE claims (
  clm_id VARCHAR(50),
  mbi VARCHAR(50),  -- Medicare Beneficiary Identifier (max 50 chars)
  ...
);

-- Example in SELECT
SELECT
  clm_id,
  mbi as medicare_beneficiary_identifier
FROM claims;

Common uses in healthcare data

Member eligibility verification and enrollment tracking
Medicare Advantage and Medicaid managed care reporting
COBRA, CHIP, and dual-eligible member management
Enrollment reconciliation and CMS submissions
Member 360 data model and longitudinal analysis

Example database column name

ISO-11179 snake_case standard

-- Recommended column name
mbi

-- Example DDL
CREATE TABLE healthcare_data (
  record_id   VARCHAR(50)   NOT NULL,
  mbi          VARCHAR(50),  -- Medicare Beneficiary Identifier (max 50 chars)
  created_dt  TIMESTAMP     NOT NULL DEFAULT NOW()
);

Column names follow the ISO-11179 naming convention: lowercase, underscore-separated, using the standard abbreviation as a prefix where applicable.

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