What is Risk Adjustment Factor (RAF) Score? Definition, Formula, and Benchmark

A Risk Adjustment Factor (RAF) score is the numeric output of a risk-adjustment model applied to an individual beneficiary. In the CMS-HCC model used for Medicare Advantage, the RAF is the sum of demographic factors (age, sex, Medicaid-dual-eligible status, long-term-institutional status, disability status) and clinical factors (HCCs derived from documented ICD-10 diagnoses) plus disease interaction factors. The model is recalibrated periodically; CMS-HCC v28 is phased in through 2025 and v28 coefficients affect RAF calculation materially compared to earlier versions.

RAF calculation is additive within HCC hierarchies but truncated by them. The hierarchies exist because CMS-HCC clusters related diagnoses and pays only for the most severe within a hierarchy. For example, a beneficiary with both HCC 19 (Diabetes without Complications, weight ~0.105) and HCC 18 (Diabetes with Chronic Complications, weight ~0.302) does not double-count — only HCC 18's weight applies because the hierarchy recognizes the more severe condition. This hierarchical structure prevents payment amplification from over-coding of mild-plus-severe combinations.

Demographic components contribute meaningfully. A 65-year-old female has baseline factor roughly 0.323; a 75-year-old female with long-term institutional status is roughly 1.254. Dual-eligibility adds 0.116–0.228 depending on age/sex combination. Disability (original Medicare entitlement via SSDI) adds approximately 0.139. The combined demographic factor establishes the floor; clinical HCCs pile on top.

For RCM and population health leaders, RAF understanding is operationally critical. Under-documented or under-coded HCCs reduce RAF, which reduces revenue in MA and reduces benchmark in MSSP/ACO REACH (affecting savings calculations). Over-documented or unsupported HCCs expose the organization to RADV audits, False Claims Act liability, and payer clawbacks. The discipline is accurate capture: every chronic condition affirmatively addressed during a calendar year must be documented per MEAT criteria and coded to specificity.

The annual RAF reset creates seasonal workflow. Every January, prior-year HCCs clear. Throughout the year, each beneficiary's HCCs must be re-established through face-to-face encounters where the clinician documents Monitor/Evaluate/Assess/Treat. RAF-accuracy programs identify historically coded but not-yet-recaptured HCCs as the year progresses ("recapture gaps") and prioritize outreach or point-of-care alerts for those members. Closing recapture gaps is high-yield: the diagnosis was clinically supported in the prior year, the patient has the condition, and only the documentation workflow prevents capture.

RAF accuracy is also a key differentiator between MA plans. Top-performing MA plans with strong provider alignment consistently show RAF in the 1.05–1.15 range; those with weak provider risk-capture workflows often sit at 0.90–1.00 even for matched populations. The ~0.15 difference on average premium of ~$1,000 PMPM equals $150 PMPM × 12 = $1,800 per member annually, scaling to tens or hundreds of millions at plan level.