G93.42 Megalencephalic leukoencephalopathy with subcortical cysts

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from G93.4 Other and unspecified encephalopathy

Excludes2 (not included here)

• alcoholic encephalopathy (G31.2)
• encephalopathy in diseases classified elsewhere (G94)
• hypertensive encephalopathy (I67.4)
• toxic (metabolic) encephalopathy (G92.8)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 200 — Friedreich and Other Hereditary Ataxias; Huntington Disease
• ESRD V24: HCC 52

MS-DRG index

Defines the logic of DRG(s) 070-072 in MDC 01.

Code annotations containing back-references to G93.42

Back-references to G93.4

• Code Also: F78.A1 SYNGAP1-related intellectual disability ("encephalopathy (G93.4-)")

Diagnosis Index entries for G93.42

• Leukoencephalopathy › megalencephalic, with subcortical cysts

Nearby codes

• G93.32 Myalgic encephalomyelitis/chronic fatigue syndrome
• G93.39 Other post infection and related fatigue syndromes
• G93.4 Other and unspecified encephalopathy
• G93.40 Encephalopathy, unspecified
• G93.41 Metabolic encephalopathy
• G93.42 Megalencephalic leukoencephalopathy with subcortical cysts (this code)
• G93.43 Leukoencephalopathy with calcifications and cysts
• G93.44 Adult-onset leukodystrophy with axonal spheroids
• G93.45 Developmental and epileptic encephalopathy
• G93.49 Other encephalopathy
• G93.5 Compression of brain