Back to search

aco attribution

aco_attr_cd
quality·Updated Jun 23, 2026

Definition

ISO-11179 Definition

The algorithm-based process of assigning Medicare fee-for-service beneficiaries to a specific Accountable Care Organization based on their historical pattern of primary care utilization, determining which beneficiaries are included in the ACO attributed population for quality measurement and financial performance calculation. CMS uses a prospective and retrospective attribution methodology for MSSP — beneficiaries are preliminarily assigned based on prior year primary care utilization and final assignment is determined after the performance year ends based on actual utilization during the year. Attribution is step-sequential, first identifying beneficiaries who received a primary care service from an ACO physician with a primary care designation and then expanding to other ACO providers.

Healthcare data teams build attribution algorithms that replicate CMS methodology to project which beneficiaries will be attributed, track attributed population characteristics for risk stratification, and analyze attribution churn to understand which beneficiaries are gained and lost between performance years.

Standard Abbreviation

aco_attr_cd

Category

quality

Production DDL — FACT_QUALITY_MEASURE

FACT_QUALITY_MEASURE.sql
CREATE OR REPLACE TABLE FACT_QUALITY_MEASURE (
    qlty_key        INTEGER        NOT NULL  -- surrogate key,
    mbr_key         INTEGER        NOT NULL  -- FK to DIM_MEMBER,
    plan_key        INTEGER        NOT NULL  -- FK to DIM_PLAN,
    meas_yr         SMALLINT                 -- measurement year,
    hedis_meas_cd   VARCHAR(20)              -- HEDIS measure code,
    denom_ind       CHAR(1)                  -- denominator eligible,
    numer_ind       CHAR(1)                  -- numerator met,
    excl_ind        CHAR(1)                  -- exclusion indicator,
    gap_open_ind    CHAR(1)                  -- care gap open,
    star_rtg_nbr    DECIMAL(3,1)             -- star rating,
    qlty_scr        DECIMAL(5,2)             -- quality score,
    perf_thrsh_pct  DECIMAL(5,2)             -- performance threshold,
    raf_scr         DECIMAL(10,3)            -- risk adjustment factor,
    outreach_cnt    SMALLINT                 -- outreach attempts,
    load_dt         TIMESTAMP_NTZ  NOT NULL  -- load timestamp
);

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

Why This Term Matters

Quality measure data determines how payers and providers are rated and reimbursed under CMS Stars, HEDIS, and value-based care contracts. Data engineers who understand quality terminology build measure calculation pipelines that correctly attribute patients, apply denominator exclusions, and flag documentation gaps before submission deadlines. Incorrect quality data directly affects star ratings, pay-for-performance bonuses, and Medicare Advantage plan bids.

Related Content

Looking for more healthcare terms?

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

Browse All Terms