What Is a RAF Score?

A Risk Adjustment Factor score — commonly called a RAF score — is a numeric value assigned to each Medicare Advantage beneficiary that predicts how much healthcare that person is expected to need in the coming year. The score is the output of the CMS-HCC risk adjustment model, and it directly determines how much money Medicare pays a health plan to care for that individual.

The concept is straightforward: sicker patients cost more to care for, so plans that enroll sicker patients should receive more funding. The RAF score is how CMS measures "sickness" for payment purposes. A score of 1.0 represents the average expected cost of a community-dwelling Medicare beneficiary. A score of 1.5 means the patient is expected to cost 50% more than average. A score of 0.7 means 30% less than average.

Most Medicare Advantage populations have average RAF scores ranging from about 0.8 to well over 2.0, depending on the demographics and health status of the enrolled population. Understanding how these scores are calculated — and how your coding directly influences them — is essential for any coder working in risk adjustment. For foundational concepts, see our introduction to HCC coding.

Why RAF Scores Matter

RAF scores are not abstract metrics — they translate directly to dollars. Every 0.01 increase in a patient's RAF score equals approximately $100 to $150 in additional annual reimbursement to the health plan, though this varies by county and payment year. For a health plan with 100,000 members, even a small systematic change in average RAF score represents millions of dollars in revenue.

This financial significance creates several important dynamics:

Accurate RAF scores ensure plans receive appropriate funding — A plan that cares for a disproportionately sick population needs adequate funding to provide quality care. Undercoding leads to underfunding.

Inaccurate RAF scores trigger CMS action — RAF scores that are systematically too high attract Risk Adjustment Data Validation audits. CMS can extrapolate audit findings across the entire membership, resulting in payment clawbacks that dwarf the value of any individual coding error.

RAF scores affect quality ratings — CMS Star Ratings and quality metrics are partially risk-adjusted. Inaccurate RAF scores distort quality comparisons between plans.

Coders are the primary influence on the diagnosis component — While demographic factors are fixed, the diagnosis-based portion of the RAF score depends entirely on what conditions are coded from clinical encounters.

Components of a RAF Score

A RAF score has two major components: demographic factors and diagnosis factors.

Demographic Factors

Demographic factors establish a baseline Risk Adjustment Factor score before any diagnoses are considered. These are assigned automatically based on CMS enrollment data — coders do not influence them:

Age and sex — CMS assigns a baseline coefficient based on the member's age band and sex. Older patients and males generally have higher baselines because they statistically use more healthcare resources.

Dual-eligible status — Members who are eligible for both Medicare and Medicaid (dual-eligible) receive a higher baseline coefficient because dual-eligible populations have higher average healthcare costs.

Institutional status — Members residing in long-term care facilities have substantially higher baselines than community-dwelling members, reflecting the intensive care needs of institutionalized populations.

Originally disabled status — Members whose original reason for Medicare entitlement was disability (rather than age) receive a modified baseline, as the disability population has different cost patterns than the aged population.

A community-dwelling, non-dual, non-disabled male aged 70 might have a demographic baseline coefficient of approximately 0.395. This means that even before any diagnoses are coded, this patient's RAF score starts at 0.395.

Diagnosis Factors (Where Coders Come In)

The diagnosis component is where medical coders have direct impact. Each HCC category has a coefficient (weight) that adds to the demographic baseline:

Each HCC's coefficient is added to the baseline — If a patient has HCC 37 (Diabetes with Chronic Complications) with a V28 coefficient of approximately 0.302, that 0.302 is added to the demographic baseline.

Multiple HCCs sum together — A patient with HCC 37 (0.302), HCC 221 (heart failure, 0.368), and HCC 280 (Chronic Obstructive Pulmonary Disease, 0.328) would have all three coefficients added to the demographic baseline.

Hierarchies remove lower-severity duplicates — If the same patient also had HCC 38 (diabetes without complications, 0.105), the hierarchy would remove HCC 38 because HCC 37 is the higher-severity diabetes category. You cannot count both.

Example calculation:

Demographic baseline (male, 70, community): 0.395

HCC 37 (Diabetes with Chronic Complications): +0.302

HCC 221 (Heart Failure): +0.368

Total RAF score: 1.065

This patient would generate approximately 6.5% more reimbursement than the average Medicare beneficiary.

How the RAF Score Calculation Works (Step by Step)

Here is the complete calculation flow from encounter to payment:

Step 1: Start with the demographic baseline — CMS assigns the age/sex/status coefficient automatically from enrollment data.

Step 2: Collect all diagnosis codes — Every ICD-10-CM code submitted from face-to-face encounters during the data collection period (typically the calendar year prior to the payment year) is gathered.

Step 3: Map codes to HCCs — Each ICD-10-CM code is crosswalked through the CMS-HCC model mapping table. Codes that map to an HCC are retained; codes that do not map are discarded for risk adjustment purposes.

Step 4: Apply hierarchies — Within each disease hierarchy, only the highest-severity HCC is kept. Lower-severity HCCs in the same group are removed.

Step 5: Sum HCC coefficients — The remaining unique HCC coefficients are added together.

Step 6: Apply disease interaction factors — Certain combinations of HCCs have interaction terms that add bonus coefficients. For example, having both heart failure and Chronic Obstructive Pulmonary Disease together may produce an interaction coefficient that recognizes the compounding effect of these conditions.

Step 7: Total all components — Demographic baseline + HCC coefficients + interaction terms = final RAF score.

The entire calculation happens at the CMS level — coders do not manually compute RAF scores. But understanding the process helps coders recognize which coding decisions have the greatest impact.

V24 vs V28 RAF Weights

During the blend transition period (Payment Year 2024 through 2027), two separate RAF scores are calculated for every patient — one using the V24 model and one using the V28 model. The final payment uses a weighted average:

Payment Year 2026: 33% V24 + 67% V28

Payment Year 2027: Expected 100% V28

The models differ in their coefficient values, even for HCCs that exist in both. Some notable patterns:

V28 generally has lower individual HCC weights but compensates with more categories and interaction terms

Severe conditions have higher weights in V28 — Advanced cancers, organ failure, and acute conditions saw weight increases

Common chronic conditions may have lower weights — Conditions that V24 weighted heavily may carry less individual weight in V28

New V28 categories added value that did not exist in V24 — Substance use disorders, for example, generate Risk Adjustment Factor value under V28 that was impossible under V24

For a comprehensive comparison of what changed, see our V24 vs V28 guide.

Using a RAF Score Calculator

Manually calculating a RAF score requires knowing every demographic coefficient and every HCC coefficient for the relevant model version, plus all applicable interaction terms. This is impractical without a calculator tool.

A good RAF calculator lets you:

Select the model version (V24 or V28)

Enter patient demographics (age, sex, dual-eligible status, institutional status)

Add HCC categories by number or by searching ICD-10 codes

See each individual factor's weight

View the total RAF score with component breakdown

Compare V24 vs V28 scores side by side

HCC Buddy offers a free RAF calculator at hccbuddy.com/raf that supports both V24 and V28 models, displays individual HCC weights, and handles hierarchy application automatically.

How to Use HCC Buddy's Free RAF Calculator

Getting started with the RAF calculator takes less than a minute:

Go to hccbuddy.com/raf — The calculator is available without signup for basic use

Select the model version — Choose V24, V28, or both to compare side by side

Enter patient demographics — Select age range, sex, dual-eligible status, and institutional/community status. The calculator applies the correct demographic baseline automatically.

Add HCC codes — Type the HCC number directly (such as "37") or search by ICD-10 code to find the mapped HCC. Each HCC you add shows its individual coefficient weight.

Review the total — The calculator displays the sum of all components: demographic baseline, individual HCC weights, interaction terms (if applicable), and total RAF score.

Compare models — View V24 and V28 scores simultaneously to understand how the blend affects this patient's total reimbursement.

The calculator handles hierarchy application automatically — if you add both HCC 37 and HCC 38, it removes HCC 38 and shows only HCC 37 in the total, just as CMS would.

Common RAF Score Misconceptions

Several misconceptions about RAF scores persist in the coding community:

"Higher RAF is always better." This is incorrect and potentially dangerous. Deliberately inflating RAF scores through inaccurate coding is healthcare fraud. The goal is an accurate RAF score that reflects the patient's true clinical burden — no more, no less. Plans with artificially inflated RAF scores face Risk Adjustment Data Validation audit exposure, payment clawbacks, and potential fraud investigations.

"RAF scores only matter for Medicare Advantage." While the CMS-HCC model applies to Medicare Advantage, the concept of risk adjustment extends beyond it. The Affordable Care Act marketplace uses a different risk adjustment model (HHS-HCC) that operates on similar principles. Medicaid managed care programs also use risk adjustment models in many states. The skills transfer across programs.

"One missed HCC does not matter much." Consider this: a single missed HCC 37 (Diabetes with Chronic Complications) with a coefficient of 0.302 represents approximately $300 or more in annual reimbursement for that one patient. Across a panel of 500 diabetic patients, systematic undercoding of diabetic complications could represent $150,000 or more in lost revenue. Every HCC matters.

"RAF scores are permanent." RAF scores are recalculated annually based on diagnoses submitted during the data collection period. Chronic conditions must be re-documented and re-coded every calendar year to continue contributing to the RAF score. A diagnosis coded in 2025 does not carry forward to 2026 automatically — it must appear in a 2026 encounter.

How Coders Impact RAF Scores

Medical coders are the bridge between clinical documentation and RAF scores. Every code you assign either adds or fails to add Risk Adjustment Factor value for a patient:

Accurate, specific coding produces accurate RAF scores — When every documented condition is captured at its highest supported specificity, the RAF score reflects the patient's true health burden.

Missing a legitimate HCC means the plan is underfunded — If a patient truly has diabetes with chronic kidney disease but the coder only captures diabetes without complications, the plan receives less funding than the patient's care requires.

Overcoding an HCC creates audit risk — If the documentation does not support the coded condition, the Risk Adjustment Data Validation audit finding results in payment recovery, often extrapolated across the plan membership.

Query programs improve both accuracy and RAF scores — When documentation is ambiguous, sending a clinical documentation improvement query to the provider is the appropriate action. Queries are expected and encouraged — they improve documentation quality and coding accuracy simultaneously.

Understanding documentation requirements is crucial for RAF score accuracy. See our MEAT criteria guide for detailed documentation standards.

For coders who want to see how their code selections translate to Risk Adjustment Factor value, HCC Buddy's encoder displays the Risk Adjustment Factor weight alongside every HCC mapping, giving you immediate visibility into the financial impact of each coding decision.

Conclusion

RAF scores are the financial backbone of risk adjustment — the mechanism through which clinical complexity translates to appropriate plan reimbursement. Understanding how they work makes you a more effective, more valuable medical coder.

The key principles: demographic factors set the baseline, HCC coefficients add diagnosis-based value, hierarchies prevent double-counting, and the V24/V28 blend applies during the transition period. Every coding decision you make either captures or misses Risk Adjustment Factor value.

Try the free RAF calculator at hccbuddy.com/raf — no signup required for basic calculations. Select your model, enter demographics, add HCCs, and see exactly how each factor contributes to the total score. For full access to all HCC Buddy tools, start your 14-day Pro trial — no credit card required.

Free RAF Score Calculator: How Risk Adjustment Factor Scores Work