G30.0 ICD-10-CM Code: Alzheimer's disease with early onset
G30.0 maps to CMS-HCC V28 127. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Other degenerative diseases of the nervous system (G30-G32)
G30.0
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAlzheimer's disease with early onset
Alzheimer's disease that begins before age 65, causing progressive memory loss and cognitive decline in younger individuals.
Buddy Insight
Alzheimer's disease with early onset (before age 65) represents a particularly impactful diagnosis due to its occurrence in younger patients who may still be in the workforce.
CMS-HCC V28
MappedHCC 127
Coefficient HCC 127: 0.341 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 52
Code-level coefficient reference
RXHCC
MappedHCC 111
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for G30.0. Check the code and parent instructions in the Code Book.
Excludes 2
Official- certain conditions originating in the perinatal period (P04-P96)Inherited from G00-G99
- certain infectious and parasitic diseases (A00-B99)Inherited from G00-G99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from G00-G99
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from G00-G99
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from G00-G99
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from G00-G99
- neoplasms (C00-D49)Inherited from G00-G99
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from G00-G99
Related Codes
Includes
Official- Alzheimer's dementia senile and presenile formsInherited from G30
Excludes 1
Official- senile degeneration of brain NEC (G31.1)Inherited from G30
- senile dementia NOS (F03.-)Inherited from G30
- senility NOS (R41.81)Inherited from G30
Code First
OfficialNo Code First sequencing instructions are included in this display for G30.0. Check the code and parent instructions in the Code Book.
Use Additional
Official- code, if applicable, to identify:Inherited from G30
- delirium, if applicable (F05)Inherited from G30
- dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)Inherited from G30
- dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)Inherited from G30
- dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)Inherited from G30
- dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)Inherited from G30
- dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)Inherited from G30
- mild neurocognitive disorder due to known physiological condition (F06.7-)Inherited from G30
Code Also
OfficialNo Code Also instructions are included in this display for G30.0. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is G30.0 an HCC code?
Yes. G30.0 (Alzheimer's disease with early onset) maps to HCC 127, Dementia, Mild or Unspecified under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.341. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: G30.0 is billable and maps to V28 HCC 127, Dementia, Mild or Unspecified. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- G30.0
- Description
- Alzheimer's disease with early onset
- HCC (V28)
- HCC 127 — Dementia, Mild or Unspecified
- RAF reference coefficient
- 0.341
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work G30.0 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for G30.0
For G30.0, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
G30.0 is the ICD-10-CM diagnosis code for alzheimer's disease with early onset. Alzheimer's disease that begins before age 65, causing progressive memory loss and cognitive decline in younger individuals. G30.0 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, G30.0 maps to Dementia, Mild or Unspecified (HCC 127) with a source-labeled community, non-dual, aged reference coefficient of 0.341. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
Alzheimer's disease with early onset, clinical onset before age 65. Per ICD-10-CM 'code first' convention, G30.0 is always sequenced before F02.8x (dementia in Alzheimer's). For G30.0, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for G30.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Alzheimer's disease with early onset, clinical onset before age 65. Per ICD-10-CM 'code first' convention, G30.0 is always sequenced before F02.8x (dementia in Alzheimer's).
- •Do not report G30.0 without the F02.8x dementia code. The pairing is mandatory, G30 alone does not capture the dementia burden for HCC purposes.
- •G30.0 itself is an Alzheimer's-disease etiology code; the paired F02.8x drives V28 HCC 127 (or HCC 125 if severe).
Clinical Significance
Alzheimer's disease with early onset (before age 65) represents a particularly impactful diagnosis due to its occurrence in younger patients who may still be in the workforce. Early-onset Alzheimer's often has stronger genetic components and may progress more rapidly than late-onset forms. It carries substantial care coordination needs including safety planning, caregiver support, and specialty neurology management.
Documentation Requirements
- ✓Documentation that symptoms began before age 65
- ✓Cognitive assessment results (e.g., MMSE, MoCA scores) demonstrating progressive decline
- ✓Neuroimaging findings consistent with Alzheimer's disease (cortical atrophy, hippocampal volume loss)
- ✓Documentation of functional status and activities of daily living impact
- ✓Current medication management (cholinesterase inhibitors, memantine) and care plan
- ✓Family history of early-onset dementia if applicable
Commonly Confused Codes
- •G30.1: Alzheimer's disease with late onset; use when onset is at age 65 or older
- •G30.9: Alzheimer's disease, unspecified; use only when age of onset is not documented
- •G31.83: Neurocognitive disorder with Lewy bodies; different dementia type with visual hallucinations and parkinsonism
- •G31.09: Other frontotemporal neurocognitive disorder; presents with personality/behavioral changes rather than memory loss
- •F02.80: Dementia in other diseases classified elsewhere, without behavioral disturbance; used as a manifestation code with G30.0 sequenced first