How we calculate RAF Estimate™

RAF (Risk Adjustment Factor) is Medicare’s way of expressing how medically complex a patient is, based on the diagnoses documented in their record. The RAF Estimate in Cortex Lens scores the diagnosis codes currently documented on the chart in front of you (the problem list’s Chronic, Acute, and Undefined sections, plus the diagnoses attached to this visit) using the official CMS-HCC model. If the documentation supports more specific or additional diagnoses, the estimate can also show a potential lift — how much higher the score could be if those suggestions belong in the chart.

It is a reference estimate: one standardized scenario applied to every chart so the numbers are comparable. It is not a statement that the patient is a Medicare beneficiary, and for patients with other insurance it has no payment meaning at all.

Your Medicare Advantage plan or ACO reports a yearly risk score for each patient. That score counts every diagnosis billed for the patient during the year, from every visit and every doctor, and the plan applies its own adjustments. The RAF Estimate counts only the diagnoses on the chart in front of you right now. For a patient who also sees specialists or spent time in the hospital, the plan’s score can be much higher.

Use the estimate to see what today’s chart supports and what the suggested changes would add. Your plan’s report is the number to use for the patient’s full year.

Click the line under the number to see each condition the estimate counted, with the chart codes behind it, the heaviest first. The conditions are the CMS model’s payment categories (HCCs), named the way CMS names them.

• Many diagnoses, like high blood pressure, are not in the model, so they never appear in the list.
• When the chart has a milder and a more severe version of the same condition, only the more severe one counts. The milder code is left out of the list.
• Age and sex, and some pairs of conditions that occur together, also add to the number. They are part of the estimate but are not listed.

We use the official CMS-HCC V28 model for payment year 2026 (2026 midyear/final mappings), with one pinned reference profile:

• Community (non-institutional), continuing enrollee
• Non-dual (no Medicaid interaction), non-ESRD
• Age and sex taken from the chart
• Patients under 65 are scored on the model’s disabled community segment; 65 and over on the aged segment
• No normalization factor and no coding-intensity adjustment — this is a raw relative factor, not a payment rate

The calculation applies the model exactly as CMS publishes it: diagnosis-to-HCC mappings with age and sex edits, condition hierarchies (a more severe condition suppresses its milder versions), disease interactions, and the condition-count variables. Potential lift is computed by re-scoring the complete code set with the suggested codes included — never by adding up per-code values, which would double-count interactions.

• Potential lift +X — a ceiling, if documentation-supported suggestions were added. Opportunity, not achievement.
• Modeled chart lift — the chart actually changed; we re-scored before and after.
• Cortex-attributed lift — the change matched a Cortex suggestion that appeared after Cortex surfaced it, and/or the biller confirmed Cortex led to it.
• Validated — an external source (the practice’s ACO or payer) confirmed the result with its own calculation. Not yet available; see status below.

Our calculator is tested for exact agreement (to the same 3-decimal rounding) with the official CMS 2026 midyear/final Python model software on a golden suite covering demographic segments, hierarchies, disease interactions, condition counts, age/sex edits, and the model’s special recodes. The suite runs on every change; the reference profile cannot ship a number unless parity passes.

External validation status: not yet validated against a practice’s ACO or payer output. Until then, every number is a modeled estimate; CMS, the applicable ACO, or the payer remains authoritative.

Model artifacts are pinned from CMS’s 2026 model software page (downloaded 2026-07-22); calculator build raf-calc-2026-07-v1. SHA-256 checksums of the exact files in use:

• Not a payment amount. Actual ACO or Medicare Advantage financial results depend on program rules, normalization, benchmarks, caps, quality scores, and contract terms that no single chart can determine.
• Not the patient’s complete risk score. It scores this chart’s documented codes, not the patient’s full claims history across the year.
• Not applicable to non-Medicare insurance. Charts known to be non-Medicare show “Not used for this insurance” beside the estimate.
• Not a target. Cortex only suggests codes the documentation supports. A higher score is never the goal; accurate, defensible documentation is.

• 2026-07-22 — Initial publication: CMS-HCC V28 (2026, 2026 midyear/final), pinned reference profile reference-2026-v28, official-software parity suite, potential-lift ceiling.
• 2026-11-05 — Lens says where the number comes from on the panel and lists the conditions counted. Diagnoses in the problem list’s Undefined section now count; they were previously left out.