Skip to main content
Call AIBook a demo

ICD-10-CM G30.9: Alzheimer's disease, unspecified

G30.9 is the billable ICD-10-CM code for alzheimer's disease, unspecified, in category G30 (Alzheimer's disease) of the Other degenerative diseases of the nervous system section. As a principal diagnosis it groups to MS-DRG 056 Degenerative Nervous System Disorders with MCC, MS-DRG 057 Degenerative Nervous System Disorders without MCC (MDC 01 MDC 01: Diseases and Disorders of the Nervous System). It maps to HCC 127 (Dementia, Mild or Unspecified) in CMS-HCC V28. 16 LCD billing and coding articles list it as covered.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM code descriptions: FY2027 (effective October 1, 2026); IPPS Table 5 (MS-DRG weights): v44 FY2027 (final rule + CN3) (effective October 1, 2026); ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); Medicare Coverage Database billing and coding articles: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: FY2028 code files, effective October 1, 2027 for the ICD-10-CM code descriptions; FY2028 final rule (August 2027), effective October 1, 2027; an April 1 interim grouper update when CMS issues one for the IPPS Table 5 (MS-DRG weights); PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027) for the ICD-10-CM to HCC mapping; weekly, every Thursday for the Medicare Coverage Database billing and coding articles.

Code
G30.9
billable FY2027 ICD-10-CM code
Category
G30 Alzheimer's disease
Chapter
6: Diseases of the nervous system (G00-G99)
CC/MCC (MS-DRG v44)
Neither
CMS-HCC V28
HCC 127
POA reporting
Required

Tabular list notes for G30.9

The tabular list has no notes on G30.9 itself; the notes below apply from its parent headings.

Inherited from G30 (Alzheimer's disease)

Includes
  • Alzheimer's dementia senile and presenile forms
Excludes1 (never coded together)
  • senile degeneration of brain NEC (G31.1)
  • senile dementia NOS (F03.-)
  • senility NOS (R41.81)
Use additional code
  • 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)
  • dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
  • mild neurocognitive disorder due to known physiological condition (F06.7-)

MS-DRG grouping when G30.9 is the principal diagnosis

MS-DRG v44 groups for G30.9 as principal diagnosis
MDCMS-DRGs
01 MDC 01: Diseases and Disorders of the Nervous System056057

The final group also depends on procedures, secondary diagnoses and discharge status; the MS-DRG lookup for G30.9 shows the full grouping logic.

CC/MCC status and inpatient edits

G30.9 is neither a CC nor an MCC under MS-DRG v44, so as a secondary diagnosis it does not raise the MS-DRG severity level. Check G30.9 against a principal diagnosis.

  • Present on admission: a POA indicator is required on inpatient claims.

CMS-HCC V28 risk adjustment

In the PY2027 mapping, G30.9 maps to HCC 127 (Dementia, Mild or Unspecified). The HCC lookup shows the RAF weight and the hierarchy.

LCD billing and coding articles that list G30.9

16 current Medicare billing and coding articles list G30.9 among the diagnoses that support medical necessity for the services they cover.

For teams evaluating QuickIntell software

Evaluate software for diagnosis coding review

If your team codes diagnoses at volume, review how QuickCode supports qualified coder review of documentation, specificity queries and the billing handoff. Confirm the code sets, settings and reviewer responsibilities during evaluation; a code reference is not a coding determination for a patient.

Evaluate QuickCode for diagnosis codingSee risk adjustment review
Book a software demoAsk about a software workflow

Optional software evaluation, not payer support or help with an individual claim. For coverage or payment decisions, use the official sources on this page. Do not include patient information in a demo booking or inquiry.

Frequently asked questions

What does ICD-10-CM G30.9 mean?

G30.9 means alzheimer's disease, unspecified. It is one of 4 billable codes under G30, alzheimer's disease.

What can't be coded with G30.9?

Excludes1 at G30: senile degeneration of brain NEC (G31.1); senile dementia NOS (F03.-); senility NOS (R41.81). These are never reported together with G30.9.

Which MS-DRG does G30.9 group to?

As the principal diagnosis, G30.9 groups to MS-DRG 056 Degenerative Nervous System Disorders with MCC, MS-DRG 057 Degenerative Nervous System Disorders without MCC (MDC 01 MDC 01: Diseases and Disorders of the Nervous System) under MS-DRG v44, before procedures and secondary diagnoses are applied.

Does G30.9 map to an HCC?

Yes: HCC 127, Dementia, Mild or Unspecified, in the PY2027 CMS-HCC V28 mapping.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

The descriptor and notes are reproduced from the FY2027 ICD-10-CM files; MS-DRG, CC/MCC and HCC facts come from the CMS FY2027 and PY2027 tables. Code from the medical record and the ICD-10-CM Official Guidelines. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.