Back to search

member county

mbr_cnty
member·Updated Jun 23, 2026

Definition

ISO-11179 Definition

The county or county-equivalent geographic area associated with a health plan member primary residential address. Member county is a critical geographic unit in Medicare Advantage because CMS sets capitation base payment rates at the county level through annual rate announcements. County-level data also supports network adequacy analysis, geographic access to care studies, and social determinants of health analytics by linking to county-level census and deprivation index data.

Healthcare data teams store mbr_cnty using FIPS county codes as VARCHAR(5) to support standardized geographic joins across CMS rate files, census data, and member enrollment tables.

Standard Abbreviation

mbr_cnty

Category

member

Production DDL — DIM_MEMBER

DIM_MEMBER.sql
CREATE OR REPLACE TABLE DIM_MEMBER (
    mbr_key           INTEGER        NOT NULL  -- surrogate key,
    mbr_id            VARCHAR(50)    NOT NULL  -- member identifier,
    mbr_first_nm      VARCHAR(100)             -- first name,
    mbr_last_nm       VARCHAR(100)             -- last name,
    mbr_birth_dt      DATE                     -- date of birth,
    mbr_gndr_cd       CHAR(1)                  -- gender code M/F/U,
    mbr_age           SMALLINT                 -- age in years,
    mbr_state_cd      CHAR(2)                  -- state code,
    mbr_zip_cd        VARCHAR(10)              -- zip code,
    mbr_elig_ind      BOOLEAN                  -- eligibility indicator,
    mbr_enrl_dt       DATE                     -- enrollment date,
    mbr_term_dt       DATE                     -- termination date,
    mbr_plan_cd       VARCHAR(20)              -- plan code,
    mbr_dual_elig_cd  VARCHAR(10)              -- dual eligibility code,
    load_dt           TIMESTAMP_NTZ  NOT NULL  -- load timestamp
);

Standard Snowflake DDL for the canonical member table. Convert to BigQuery or Databricks →

Why This Term Matters

Member and enrollment data governs who receives care and who pays for it — making it foundational to every downstream healthcare analytics workflow. Data engineers who understand member terminology build eligibility pipelines that prevent coverage gaps, correctly identify dual-eligible members, and support accurate risk adjustment submissions to CMS. Enrollment errors directly affect capitation payments and can trigger CMS corrective action plans.

Related Content

Looking for more healthcare terms?

Browse our complete library of 100,000+ standardized healthcare data terms

Browse All Terms