G30.1
BillableAlzheimer's disease with late onset
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G30.1 an HCC code?
Yes. G30.1 maps to Dementia, Mild or Unspecified under the CMS-HCC V28 risk adjustment model.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for G30.1
For G30.1 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G30.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G30.1 is the ICD-10-CM diagnosis code for alzheimer's disease with late onset. Alzheimer's disease that begins at age 65 or older, the most common form of dementia in elderly patients. G30.1 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering other degenerative diseases of the nervous system (g30-g32).
Under the CMS-HCC V28 risk adjustment model, G30.1 maps to Dementia, Mild or Unspecified (HCC 127) with a community, non-dual, aged base RAF weight of 0.464. G30.1 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify the patient's age at symptom onset to confirm late-onset classification. Because G30.1 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G30.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the patient's age at symptom onset to confirm late-onset classification
- •Document cognitive decline, memory loss, and functional impairment to support the diagnosis
Clinical Significance
Alzheimer's disease with late onset is the most common form of dementia, affecting patients age 65 and older. It drives significant healthcare resource utilization including cognitive care, safety monitoring, medication management, and caregiver support services. Accurate capture is critical for risk adjustment as these patients have progressive care needs that increase over time.
Documentation Requirements
- ✓Documentation that symptoms began at age 65 or older
- ✓Cognitive testing results showing progressive decline (MMSE, MoCA)
- ✓Clinical evaluation or neuroimaging supporting Alzheimer's diagnosis
- ✓Current functional status and impact on activities of daily living
- ✓Medication management documentation (cholinesterase inhibitors, memantine)
- ✓Assessment for behavioral and psychological symptoms of dementia
Commonly Confused Codes
- •G30.0 — Alzheimer's disease with early onset; use when onset is before age 65
- •G30.9 — Alzheimer's disease, unspecified; avoid when onset age is documented
- •F03.90 — Unspecified dementia without behavioral disturbance; too vague if Alzheimer's is confirmed
- •G31.83 — Neurocognitive disorder with Lewy bodies; distinct dementia with hallucinations and motor symptoms
- •F01.50 — Vascular dementia without behavioral disturbance; caused by cerebrovascular disease, not Alzheimer's pathology