DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

G23 Other degenerative diseases of basal ganglia

  • Header · not billable

G23 is not billable. The category heads 6 billable codes in FY2027: the 6 codes directly below it.

Index → code

  • Déjérine-Thomas atrophy → G23.8
  • Fahr disease (of brain) → G23.8
  • Hallervorden-Spatz disease → G23.0

Where it sits

  1. Chapter 6 Diseases of the nervous system (G00-G99)
  2. G20-G26 Extrapyramidal and movement disorders (G20-G26)
  3. G23 Other degenerative diseases of basal ganglia
Billable codes
6
Subdivisions
6
CC / MCC codes
6 / 0
HCC V28 codes
6
New FY2027
0
Index entries
26

Codes in G23

  1. G23.0
    Hallervorden-Spatz disease
    BillableCC199
    Inclusion terms 1

    Inclusion terms

    • Pigmentary pallidal degeneration
  2. G23.1
    Progressive supranuclear ophthalmoplegia [Steele-Richardson-Olszewski]
    BillableCC199
    Inclusion terms 1

    Inclusion terms

    • Progressive supranuclear palsy
  3. G23.2
    Striatonigral degeneration
    BillableCC199
  4. G23.3
    Hypomyelination with atrophy of the basal ganglia and cerebellum
    BillableCC199
    Inclusion terms 2

    Inclusion terms

    • H-ABC
    • TUBB4A-related neurologic disorders
  5. G23.8
    Other specified degenerative diseases of basal ganglia
    BillableCC199
    Inclusion terms 1

    Inclusion terms

    • Calcification of basal ganglia
  6. G23.9
    Degenerative disease of basal ganglia, unspecified
    BillableCC199

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column.

Instructions

At G23

Excludes2

  • multi-system degeneration of the autonomic nervous system (G90.3) G90.3

Notes that also apply

Chapter 6 instructions (Excludes2 8): printed on the chapter 6 page.

Index entries

  • Hallervorden-Spatz disease → G23.0
  • Steele-Richardson-Olszewski disease or syndrome → G23.1
  • Willige-Hunt disease or syndrome → G23.1
  • H-ABC (hypomyelination with atrophy of the basal ganglia and cerebellum) → G23.3
  • Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) → G23.3
  • Déjérine-Thomas atrophy → G23.8
  • Fahr disease (of brain) → G23.8
  • Degeneration, degenerativepallidal pigmentary (progressive) → G23.0
  • Syndromepigmentary pallidal degeneration (progressive) → G23.0
  • Ophthalmoplegiasupranuclear, progressive → G23.1
  • Palsyprogressive supranuclear → G23.1
  • Paralysis, paralytic (complete) (incomplete)supranuclear (progressive) → G23.1
  • Degeneration, degenerativestriatonigral → G23.2
  • Atrophy, atrophic (of)Déjérine-Thomas → G23.8
  • Atrophy, atrophic (of)olivopontocerebellar → G23.8
  • Calcificationbasal ganglia → G23.8
  • Degeneration, degenerativeolivopontocerebellar (hereditary) (familial) → G23.8
  • Disease, diseasedFahr (of brain) → G23.8
  • Degeneration, degenerativebasal nuclei or ganglia → G23.9
  • Degeneration, degenerativepigmentary (diffuse) (general)pallidal (progressive) → G23.0
  • Palsybulbar (progressive) (chronic)supranuclear (progressive) → G23.1
  • Paralysis, paralytic (complete) (incomplete)progressive (atrophic) (bulbar) (spinal)supranuclear → G23.1
  • Disorder (of)neurological NECTUBB4A-related → G23.3
  • Degeneration, degenerativebasal nuclei or gangliaspecified NEC → G23.8
  • Disease, diseasedbasal gangliadegenerative → G23.9
  • Disease, diseasedbasal gangliadegenerativespecified NEC → G23.8

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy