Dementia HCC Coding Guide
Complete HCC coding guide for Dementia (F01-F03) including Alzheimer's, vascular, and other dementias with ICD-10 to HCC mapping, V28 RAF weights, and documentation tips.
Quick Facts
HCC Categories
HCC 149 — Dementia, Severe
HCC 150 — Dementia, Moderate or Less Severe
RAF Weight Range
0.316 – 0.637
Community, non-dual, aged (V28)
Model
CMS-HCC V28 (PY2026 — 100% phase-in)
6 ICD-10 codes map to payment HCCs
Overview
Dementia encompasses a group of progressive neurocognitive disorders affecting approximately 7 million Americans, with Alzheimer's disease being the most common type. Under CMS-HCC V28, dementia maps to HCC 149 (Dementia, Severe) or HCC 150 (Dementia, Moderate or Less Severe), depending on the documented severity. Accurate coding requires specifying the type of dementia (Alzheimer's, vascular, Lewy body, frontotemporal), the severity, and whether behavioral disturbances are present. The coding of dementia requires careful documentation of cognitive assessment results, functional status, and the presence or absence of behavioral and psychological symptoms. Coders must also capture any co-occurring delirium when documented.
ICD-10 to HCC Mapping
| ICD-10 Code | Description | Billable | HCC Mapping |
|---|---|---|---|
| F01.50 | Vascular dementia, unspecified severity, without behavioral disturbance | Yes | HCC 150 |
| F01.511 | Vascular dementia, unspecified severity, with agitation | Yes | HCC 150 |
| F02.80 | Dementia in other diseases classified elsewhere, unspecified severity, without behavioral disturbance | Yes | HCC 150 |
| F02.811 | Dementia in other diseases classified elsewhere, unspecified severity, with agitation | Yes | HCC 150 |
| F03.90 | Unspecified dementia, unspecified severity, without behavioral disturbance | Yes | HCC 150 |
| G30.0 | Alzheimer's disease with early onset | Yes | Code first, use with F02 |
| G30.1 | Alzheimer's disease with late onset | Yes | Code first, use with F02 |
| G30.9 | Alzheimer's disease, unspecified | Yes | Code first, use with F02 |
| G31.83 | Dementia with Lewy bodies | Yes | Code first, use with F02 |
| F01.51 | Vascular dementia, unspecified severity, with behavioral disturbance | Yes | HCC 150 |
RAF weights are community, non-dual, aged base coefficients from the CMS-HCC V28 model (PY2026). Verify against the latest CMS rate announcement for payment calculations.
Documentation Tips
Document the specific type of dementia: Alzheimer's (G30 + F02), vascular (F01), Lewy body (G31.83 + F02), frontotemporal (G31.09 + F02).
Specify the severity of dementia: mild, moderate, or severe based on cognitive assessment tools (MMSE, MoCA).
Document any behavioral disturbances: agitation, wandering, aggression, or psychotic symptoms — these affect code selection.
For Alzheimer's disease, always code both the Alzheimer's etiology (G30.x) and the dementia manifestation (F02.x).
Include the most recent cognitive assessment score and date to support the documented severity level.
Record the patient's functional status (ADLs/IADLs) to support the severity documentation.
Document current medications including cholinesterase inhibitors and memantine to satisfy MEAT treatment criteria.
Note caregiver involvement and any advance directive discussions as part of the care plan.
Common Coding Mistakes
Coding F03.90 (unspecified dementia) when the type and etiology are documented — always code to the specific type.
Forgetting to code both the Alzheimer's disease code (G30.x) and the dementia manifestation code (F02.x) — both are required.
Not capturing behavioral disturbances when they are documented, missing the opportunity for more specific coding.
Failing to document dementia severity, which is required under V28 for proper HCC stratification between HCC 149 and HCC 150.
V24 to V28 Changes
V28 split dementia into two severity-based HCCs: HCC 149 (Dementia, Severe) with a significantly higher RAF weight, and HCC 150 (Dementia, Moderate or Less Severe). Under V24, all dementia types mapped to a single HCC 52 (Dementia) regardless of severity. This V28 change makes severity documentation critical — severe dementia (HCC 149) carries approximately double the RAF weight of moderate or less severe dementia (HCC 150). The ICD-10-CM codes with severity specifiers (7th character) now drive the HCC tier assignment.
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