Risk Adjustment
Hierarchical Condition Categories(HCC)
CMS-defined groups of related ICD-10-CM codes that drive Medicare Advantage and ACA risk-adjusted payments.
Definition
Hierarchical Condition Categories (HCCs) are diagnosis groupings that the Centers for Medicare & Medicaid Services (CMS) uses to compute risk-adjusted capitation payments to Medicare Advantage and ACA plans. Each HCC bundles a set of ICD-10-CM codes that imply roughly equivalent expected cost. CMS publishes the HCC tables annually (the v22 "clinical revision" model and the v28 model phased in across PY2024-PY2026 are the two in active use as of 2025).
Each HCC carries a weight (a coefficient that contributes to a patient's Risk Adjustment Factor, or RAF). The hierarchical part of the name means that within a clinical family, more severe conditions trump less severe ones (e.g., HCC 18 "Diabetes with chronic complications" outranks HCC 19 "Diabetes without complication" in v24).
When you submit ICD-10 codes to AutoICD's audit endpoint with hcc enabled, the engine maps each code to its HCC under both v22 and v28, computes the contribution to RAF, and flags conditions that were documented but not coded (gap capture).
When to use
- •You operate or partner with a Medicare Advantage plan, ACO REACH, or Medicaid risk program.
- •You run prospective or retrospective chart reviews and want to surface HCC-eligible diagnoses missed in the encounter.
- •You need to estimate annualized PMPM impact of a missed code (HCC weight x national base rate).
Try it in AutoICD API
Run a chart audit with HCC gap capture
curl -X POST https://autoicdapi.com/v1/audit \
-H "Authorization: Bearer $AUTOICD_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"text": "65F with diabetes mellitus type 2 with diabetic nephropathy and chronic kidney disease stage 3.",
"submitted_codes": ["E11.9"],
"capabilities": ["hcc"]
}'Language: bash. View full API docs · Get an API key.