RAF Score Calculation: A Step-by-Step Guide

What Is a RAF Score?

The Risk Adjustment Factor (RAF) score is a numerical value assigned to each Medicare Advantage beneficiary that predicts their expected healthcare costs relative to the average Medicare beneficiary. CMS uses RAF scores to determine how much a Medicare Advantage plan is paid for each member.

A RAF score of 1.0 means the beneficiary is expected to cost the same as the average Medicare beneficiary. A score of 1.5 means 50% more costly, while a score of 0.8 means 20% less costly.

Components of a RAF Score

1. Demographic Factors

Every beneficiary starts with a baseline score determined by:

2. HCC Coefficients

Each HCC category carries a coefficient (weight) that adds to the baseline:

3. Disease Interaction Terms

Certain combinations of HCCs generate additional coefficients:

Step-by-Step Calculation

Step 1: Establish the Demographic Baseline

Start with the appropriate demographic coefficient based on age, sex, and eligibility.

Example: A 72-year-old female, community-dwelling, non-dual-eligible has a V28 demographic baseline of 0.395 (CNA female age 70-74, V28_CE_Relative_Factors.csv).

Step 2: Add HCC Coefficients

For each confirmed HCC, add its V28 CNA coefficient:

Running total: 0.395 + 0.166 + 0.360 + 0.319 = 1.240

Step 3: Apply Hierarchies

Check if any HCCs are in the same hierarchy. If so, only the highest-severity HCC in that hierarchy is kept.

Step 4: Add Interaction Terms

Check for disease interactions. Diabetes plus Heart Failure adds the V28 DIABETES_HF_V28 CNA interaction term of +0.112. Heart Failure plus Chronic Lung Disorder also adds the HF_CHR_LUNG_V28 CNA interaction term of +0.078 for this example.

Running total: 1.240 + 0.112 + 0.078 = 1.430

Step 5: Apply Payment Model Blend

Payment Year 2026 is scored on 100% V28, so there is no blend step for current-year payment. The final RAF score is the V28 score. (During the transition, CMS blended the models; PY2025 was the last blend year at 33% V24 / 67% V28.)

To run this same math on a real patient without a spreadsheet, the free RAF score calculator applies the current V28 coefficients, hierarchies, and interaction terms automatically.

Why RAF Accuracy Matters

For Health Plans

For Coders

How HCC Buddy Helps with RAF Scores

Every code lookup in HCC Buddy shows the RAF weight for both V24 and V28 models. This lets coders immediately understand the risk adjustment impact of each code they assign.

See RAF weights 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.