What Is HCC Coding? A Complete Guide for 2026
Learn what HCC coding is, why it matters for risk adjustment, and how medical coders use ICD-10-CM to HCC mapping in their daily workflow.
Medically reviewed by Jess P., CPC
Reviewed: March 7, 2026
What Is HCC Coding?
Hierarchical Condition Category (HCC) coding is a risk adjustment methodology used by the Centers for Medicare and Medicaid Services (CMS) to predict future healthcare costs for patients. Medical coders play a critical role in this process by ensuring that every diagnosis is accurately captured using ICD-10-CM codes, which then map to specific HCC categories.
Why HCC Coding Matters
HCC coding directly impacts how much Medicare Advantage plans are reimbursed for each patient. When a patient's chronic conditions are accurately documented and coded, the plan receives appropriate funding to cover that patient's expected healthcare needs.
Key reasons HCC coding is essential:
How ICD-10-CM Codes Map to HCCs
Not every ICD-10-CM code maps to an HCC. Of the approximately 72,000 ICD-10-CM codes, only a subset are HCC-relevant. The mapping process works as follows:
1. Provider documents a condition during a face-to-face encounter
2. Coder assigns the most specific ICD-10-CM code supported by documentation
3. The code is crosswalked to the CMS-HCC model (V24 or V28)
4. Each HCC has a weight (coefficient) that contributes to the patient's RAF score
5. The RAF score determines the plan's reimbursement for that member
Example
A patient with Type 2 Diabetes Mellitus with diabetic chronic kidney disease would be coded as:
HCC Coding Models: V24 vs V28
CMS is transitioning from the V24 model to the V28 model. In 2026, the blended model uses:
Key differences in V28:
MEAT Criteria for HCC Coding
For an HCC to be captured, the documentation must meet the MEAT criteria:
Simply listing a condition in the past medical history is not sufficient for HCC capture.
How HCC Buddy Helps
HCC Buddy is built specifically for HCC coders. Every ICD-10-CM code in our encoder shows:
Try it free, search any ICD-10 code and see the HCC mapping instantly at hccbuddy.com/encoder.
Free resource: Download the HCC Coding Cheat Sheet, a printable V28 quick reference with top HCC categories and documentation tips.
Jess P., CPC
Certified Professional Coder
Jess reviews HCC Buddy editorial content for accuracy against the current CMS-HCC model and the active FY ICD-10-CM tabular release.
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