E03.5 Myxedema coma

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

Applies from E03 Other hypothyroidism

Excludes1 (never code together)

• iodine-deficiency related hypothyroidism (E00-E02)
• postprocedural hypothyroidism (E89.0)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 202 — Coma, Brain Compression/Anoxic Damage
• CMS-HCC V22: HCC 23 — Other Significant Endocrine and Metabolic Disorders
• RxHCC V08: HCC 44 — Thyroid Disorders
• ESRD V24: HCC 23

MS-DRG index

Defines the logic of DRG(s) 080-081 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 780.01 Coma (approximate)

Code annotations containing back-references to E03.5

Back-references to E03.5

• Code First: D63.8 Anemia in other chronic diseases classified elsewhere ("hypothyroidism (E00.0-E03.9)")
• Code First: G32.8 Other specified degenerative disorders of nervous system in diseases classified elsewhere ("cerebral degeneration (due to) hypothyroidism (E00.0-E03.9)")

Back-references to E03

• Code First: F02 Dementia in other diseases classified elsewhere ("hypothyroidism, acquired (E00-E03.-)")
• Code First: G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema ("hypothyroidism (E03.-)")
• Code First: G63 Polyneuropathy in diseases classified elsewhere ("endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34)")
• Code First: H28 Cataract in diseases classified elsewhere ("myxedema (E03.-)")
• Code Also: I27.29 Other secondary pulmonary hypertension ("hypothyroidism (E00-E03)")
• Code First: M14.8 Arthropathies in other specified diseases classified elsewhere ("hypothyroidism (E00-E03)")

Diagnosis Index entries for E03.5

• Coma › myxedematous
• Myxedema (adult) (idiocy) (infantile) (juvenile) › coma

Nearby codes

• E03.0 Congenital hypothyroidism with diffuse goiter
• E03.1 Congenital hypothyroidism without goiter
• E03.2 Hypothyroidism due to medicaments and other exogenous substances
• E03.3 Postinfectious hypothyroidism
• E03.4 Atrophy of thyroid (acquired)
• E03.5 Myxedema coma (this code)
• E03.8 Other specified hypothyroidism
• E03.9 Hypothyroidism, unspecified