2027 ICD-10-CM Diagnosis Code G30.9Alzheimer's disease, unspecified

ICD-10-CM Codes›G00–G99›G30-G32›G30

ICD-10-CM G30.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G30.9 is a billable ICD-10-CM diagnosis code for Alzheimer's disease, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 56 through 57. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurocognitive disorders.

For Medicare Advantage risk adjustment, G30.9 maps to CMS-HCC Category 127 (Dementia, Mild or Unspecified) under the V28 model, adding a risk factor of about 0.341 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
G30.9
Billable Status
Yes — Valid for Submission
Code Describes
Alzheimer's disease, unspecified
Short Description
Alzheimer's disease, unspecified
Same as the full description in the CMS dataset.
Parent Code
G30
Alzheimer's disease

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG30-G32Other degenerative diseases of the nervous system
CategoryG30Alzheimer's disease
This CodeG30.9Alzheimer's disease, unspecified

Medicare Risk Adjustment (HCC)Billing

G30.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 127— Dementia, Mild or Unspecified
Payment HCC · PY 2027 one of 65 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.341
community, non-dual, aged · ranges 0.000–0.438 across segments
Hierarchy
Superseded by HCC 125 and HCC 126
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 52
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
ESRD (V21): HCC 52 · ESRD (V24): HCC 52
ESRD V21 weights: 0.045 dialysis, 0.000–0.328 functioning graft · ESRD V24 weights: 0.042 dialysis, 0.000–0.399 functioning graft
Part D (RxHCC)
RxHCC 111 — Alzheimer's Disease
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Alzheimer's disease
  • Alzheimer's disease with altered behavior
  • Alzheimer's disease with delirium
  • Alzheimer's disease with delusions
  • Alzheimer's disease with depressed mood
  • Alzheimer's disease with progressive aphasia
  • Alzheimer's disease with psychosis
  • Dementia of the Alzheimer type with behavioral disturbance
  • Dementia with behavioral disturbance
  • Focal Alzheimer's disease
  • Late onset Alzheimer's dementia with behavioral disturbance
  • Progressive aphasia

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G30.9: its own notes plus those printed at G30 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From G30 Alzheimer's disease applies to 4 codes
  • Alzheimer's dementia senile and presenile forms

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From G30 Alzheimer's disease applies to 4 codes
  • senile degeneration of brain NEC (G31.1)
  • senile dementia NOS (F03.-)
  • senility NOS (R41.81)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From G30 Alzheimer's disease applies to 4 codes

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G30.9, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming G30.9: they are not reported together with it, unless the two conditions are unrelated.

  • G31.1 Senile degeneration of brain, not elsewhere classified
    Alzheimer's disease (G30.-) names G30.-, which includes this code

Code First 3

These codes say to code first a condition named in the note, and G30.9 is one of the conditions named.

  • F02 Dementia in other diseases classified elsewhere
    Alzheimer's (G30.-) names G30.-, which includes this code
  • F06.7 Mild neurocognitive disorder due to known physiological condition
    Alzheimer's disease (G30.-) names G30.-, which includes this code
  • Z91.83 Wandering in diseases classified elsewhere
    Alzheimer's disease (G30.-) names G30.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS011
Neurocognitive disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Alzheimer Disease

    a degenerative disease of the brain characterized by the insidious onset of dementia. impairment of memory, judgment, attention span, and problem solving skills are followed by severe apraxias and a global loss of cognitive abilities. the condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of senile plaques; neurofibrillary tangles; and neuropil threads. (from adams et al., principles of neurology, 6th ed, pp1049-57)

Patient EducationClinical

Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia among older people. Dementia is a brain disorder that seriously affects thinking and memory skills. If you have AD, it can impair your ability to reason or learn new skills until it becomes difficult to complete daily activities.

The full article covers:

  • What is Alzheimer's disease?
  • What are the symptoms of Alzheimer's disease?
  • Who is more likely to develop Alzheimer's disease?
  • How is Alzheimer's disease diagnosed?
  • What are the treatments for Alzheimer's disease?
  • Can Alzheimer's disease be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G30.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
331.0 Alzheimer's disease
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G30.9Overview

What is the ICD-10 code for Alzheimer's disease, unspecified?

The ICD-10-CM code for Alzheimer's disease, unspecified is G30.9 (sometimes written as G309). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G30.9 (Alzheimer's disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Alzheimer's disease, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G30.9 group to?

When Alzheimer's disease, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 57, 56, with relative weights from 1.2835 to 2.2649 depending on complications. Higher weights mean higher Medicare reimbursement.

Can G30.9 be reported with G31.1?

Not as a rule. The Excludes1 note at G30, which applies to G30.9, lists "senile degeneration of brain NEC (G31.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does G30.9 need an additional code?

When the condition applies, yes. The Use Additional Code note at G30, which applies to G30.9, reads: code, if applicable, to identify: delirium, if applicable (F05); dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4); dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-); dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3); dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2); and 2 more listed in the Instructional Notes section. The additional code is reported after G30.9.

What HCC is G30.9?

G30.9 (Alzheimer's disease, unspecified) maps to CMS-HCC Category 127 (Dementia, Mild or Unspecified), commonly written as HCC 127, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 52 under the retired V24 model. It also maps in the ESRD (V21) and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 111.

Does G30.9 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, G30.9 adds a risk adjustment factor of about 0.341 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.000 to 0.438 depending on the payment segment). A more severe related category (HCC 125 and HCC 126) supersedes it when both are reported. See the full factor table on the HCC 127 category page.