G30.9 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

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupG30.9

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Other degenerative diseases of the nervous system (G30-G32)

G30.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Alzheimer's disease, unspecified

Alzheimer's disease without specification of the stage or type; the most common form of dementia causing progressive memory loss and cognitive decline.

Buddy Insight

Alzheimer's disease, unspecified, captures confirmed Alzheimer's diagnoses where the onset type or variant has not been documented.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 127

Dementia, Mild or Unspecified

Coefficient HCC 127: 0.341 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

Mapped

HCC 52

Dementia Without Complication

Code-level coefficient reference

RXHCC

Mapped

HCC 111

Alzheimer's Disease

Code-level coefficient reference

Code Book Path

Official

G30Alzheimer's disease G30.9Alzheimer's disease, unspecified

Inclusion Terms

Official

No inclusion terms are included in this display for G30.9. 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

Official

G30.0Alzheimer's disease with early onset G30.1Alzheimer's disease with late onset G30.8Other Alzheimer's disease

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

Official

No Code First sequencing instructions are included in this display for G30.9. 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

Official

No Code Also instructions are included in this display for G30.9. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Provider documentation confirming Alzheimer's disease diagnosis

Cognitive assessment demonstrating decline (MMSE, MoCA, or equivalent)

Evidence of progressive memory loss and functional impairment

Current medication management and care plan

MEAT Support

HCC Buddy guidance

Provider documentation confirming Alzheimer's disease diagnosis

Cognitive assessment demonstrating decline (MMSE, MoCA, or equivalent)

Evidence of progressive memory loss and functional impairment

Current medication management and care plan

Audit Caution

HCC Buddy guidance

Accepting G30.9 without querying the provider for onset age to assign G30.0 or G30.1

Using G30.9 when documentation states 'senile dementia' without a confirmed Alzheimer's diagnosis

Forgetting to add the manifestation code F02.80/F02.81 for the associated dementia

Coding Alzheimer's based on family history alone without clinical diagnosis

Common Mistakes

HCC Buddy guidance

G30.0 — Alzheimer's disease with early onset; query provider if onset age is available

G30.1 — Alzheimer's disease with late onset; query provider if onset age is documented

F03.90 — Unspecified dementia; too vague if Alzheimer's has been specifically diagnosed

G31.84 — Mild cognitive impairment; a milder condition that may precede Alzheimer's but is not the same

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 G30.9 an HCC code?

Yes. G30.9 (Alzheimer's disease, unspecified) 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: G30.9 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: G30.9
Description: Alzheimer's disease, unspecified
HCC (V28): HCC 127 — Dementia, Mild or Unspecified
RAF reference coefficient: 0.341
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 127, Dementia, Mild or Unspecified

0.341

ESRDHCC 52, Dementia Without Complication

Not separately weighted

RxHCCHCC 111, Alzheimer's Disease

Not separately weighted

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 G30.9 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for G30.9

For G30.9, 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

G30.9 is the ICD-10-CM diagnosis code for alzheimer's disease, unspecified. Alzheimer's disease without specification of the stage or type; the most common form of dementia causing progressive memory loss and cognitive decline. G30.9 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, G30.9 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, unspecified, provider documents Alzheimer's without specifying early vs late onset. Pair with F02.8x per 'code first' convention. For G30.9, 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 G30.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Alzheimer's disease, unspecified, provider documents Alzheimer's without specifying early vs late onset. Pair with F02.8x per 'code first' convention.
•Do not default to G30.9 when the chart supports early (G30.0) or late (G30.1) onset. Onset specificity is a minor chart-quality improvement.

Clinical Significance

Alzheimer's disease, unspecified, captures confirmed Alzheimer's diagnoses where the onset type or variant has not been documented. While it carries the same HCC value as more specific Alzheimer's codes, it represents a documentation improvement opportunity. Accurate capture still ensures proper risk adjustment for these patients with progressive cognitive decline requiring substantial care resources.

Documentation Requirements

✓Provider documentation confirming Alzheimer's disease diagnosis
✓Cognitive assessment demonstrating decline (MMSE, MoCA, or equivalent)
✓Evidence of progressive memory loss and functional impairment
✓Current medication management and care plan
✓Assessment for associated behavioral or psychological symptoms

Commonly Confused Codes

•G30.0: Alzheimer's disease with early onset; query provider if onset age is available
•G30.1: Alzheimer's disease with late onset; query provider if onset age is documented
•F03.90: Unspecified dementia; too vague if Alzheimer's has been specifically diagnosed
•G31.84: Mild cognitive impairment; a milder condition that may precede Alzheimer's but is not the same
•R41.81: Age-related cognitive decline; normal aging, not Alzheimer's disease