G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema

Billable ICD-10-CM code, FY2026.

Code first

• underlying disease, such as:
• hypothyroidism (E03.-)
• myxedematous congenital iodine deficiency (E00.1)

Risk adjustment (HCC)

• RxHCC V08: HCC 112 — Dementia, Except Alzheimer's Disease
• ESRD V24: HCC 52

MS-DRG index

Defines the logic of DRG(s) 056-057 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 331.7 Cerebral degeneration in diseases classified elsewhere (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Manifestation codes as principal diagnosis: Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and are not allowed as principal diagnosis.

Code annotations containing back-references to G13.2

Back-references to G13.2

• Type 1 Excludes: G32.81 Cerebellar ataxia in diseases classified elsewhere ("systemic atrophy primarily affecting the central nervous system in myxedema (G13.2)")

Diagnosis Index entries for G13.2

• Ataxia, ataxy, ataxic › cerebellar (hereditary) › in › myxedema
• Atrophy, atrophic (of) › systemic affecting central nervous system › in › myxedema

Nearby codes

• G13 Systemic atrophies primarily affecting central nervous system in diseases classified elsewhere
• G13.0 Paraneoplastic neuromyopathy and neuropathy
• G13.1 Other systemic atrophy primarily affecting central nervous system in neoplastic disease
• G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema (this code)
• G13.8 Systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere