RAF Score Calculation: A Step-by-Step Guide
Understand how Risk Adjustment Factor scores are calculated, what components make up a RAF score, and why accurate RAF scoring matters for Medicare Advantage plans.
By the HCC Buddy Coding Team
Updated: August 25, 2026
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:
- Age, Older beneficiaries generally have higher baseline scores
- Sex, Male and female beneficiaries have different baseline coefficients
- Eligibility status, Whether the beneficiary is community-dwelling, institutionalized, or new enrollee
- Medicaid dual-eligible status, Beneficiaries eligible for both Medicare and Medicaid receive different coefficients
- Disability status, Originally disabled beneficiaries under 65 have separate factors
2. HCC Coefficients
Each HCC category carries a coefficient (weight) that adds to the baseline:
- Higher-severity conditions have higher coefficients
- Only one HCC per hierarchy is counted (the most severe)
- Coefficients differ between the V24 and V28 models
- The coefficients represent the incremental cost of that condition
3. Disease Interaction Terms
Certain combinations of HCCs generate additional coefficients:
- Diabetes + Heart Failure, Having both conditions together adds an interaction term beyond the individual HCC weights
- COPD + Heart Failure, Another common interaction that increases the RAF score
- These interactions recognize that multiple chronic conditions create compounding healthcare costs
Worked member-score example
> RAF Calculator: The RAF Calculator supports CMS-HCC V28 for Payment Year 2026 and requires complete member context. HCC Buddy shows a score only after the server confirms the required source and calculation checks. If a check is unavailable or does not pass, no score is shown.
Static code-level coefficients are references, not member totals. Historical PY2025 V24 stays reference-only.
Why RAF Accuracy Matters
For Health Plans
- Undercoded patients, The plan receives less funding than needed to cover actual healthcare costs
- Overcoded patients, Creates audit risk and potential repayment obligations
- Population health, Inaccurate RAF scores distort the plan's understanding of its population's health burden
For Coders
- Accurate capture, Assigning only conditions reportable under the record and applicable rules
- Specificity, Using the most specific ICD-10-CM code to get the correct HCC mapping
- Accuracy, Only coding conditions that are supported by documentation
HCC Buddy RAF Calculator
> RAF Calculator: The RAF Calculator supports CMS-HCC V28 for Payment Year 2026 and requires complete member context. HCC Buddy shows a score only after the server confirms the required source and calculation checks. If a check is unavailable or does not pass, no score is shown.
Free resource: Download the HCC Coding Cheat Sheet, a printable V28 mapping and documentation reference.
Frequently asked questions
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 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.
What are the components of a RAF score?
A RAF score has three components. First, a demographic baseline determined by age, sex, eligibility status (community vs. institutional), Medicaid dual-eligible status, and disability status. Second, HCC coefficients, each qualifying HCC adds its coefficient to the baseline, with only the most severe HCC per disease hierarchy counted. Third, disease interaction terms, certain HCC combinations, such as Diabetes plus Heart Failure or COPD plus Heart Failure, generate additional coefficients that recognize compounding healthcare costs.
How do you calculate a RAF score step by step?
For a CY2026 non-PACE score, select the correct demographic segment, add source-verified V28 coefficients for supported HCCs, apply hierarchy rules, and add only the interaction terms supported by the model source. PACE follows a separate CY2026 blend and cannot be represented by one V28 calculation.
Why does RAF score accuracy matter for health plans and coders?
Unsupported or inaccurate diagnosis data can distort risk scores and create audit or repayment risk. Coding accuracy starts with the code supported by the record and official classification, then uses the applicable model, segment, hierarchy, and interaction rules. Do not choose specificity for a larger coefficient, and do not treat MEAT as a universal reportability rule.
Related Tools
RAF Calculator
CMS-HCC V28 Payment Year 2026 scoring with complete member context. No score is shown unless the required source and calculation checks pass.
ICD-10 Encoder
Look up ICD-10-CM codes with current V28 mapping and source periods. Historical PY2025 V24 stays reference-only, and code-level coefficients are not member totals.
HCC Buddy Coding Team
Editorial
Every HCC Buddy article is checked against the current CMS-HCC model and the active FY ICD-10-CM tabular release before it publishes.
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