G73.3 Myasthenic syndromes in other diseases classified elsewhere

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

Code first

• underlying disease, such as:
• neoplasm (C00-D49)
• thyrotoxicosis (E05.-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 196 — Myasthenia Gravis without (Acute) Exacerbation and Other Myoneural Disorders
• CMS-HCC V22: HCC 75 — Myasthenia Gravis/Myoneural Disorders, Inflammatory and Toxic Neuropathy
• RxHCC V08: HCC 153 — Myasthenia Gravis and Other Myoneural Disorders
• ESRD V24: HCC 75

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 358.1 Myasthenic syndromes in diseases classified elsewhere

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 G73.3

Back-references to G73

• Code First: M62.84 Sarcopenia ("disorders of myoneural junction and muscle disease in diseases classified elsewhere (G73.-)")

Diagnosis Index entries for G73.3

• Myasthenia › syndrome › in › neoplastic disease
• Myasthenia › syndrome › in › pernicious anemia
• Myasthenia › syndrome › in › thyrotoxicosis
• Myasthenia › syndrome › in › thyrotoxicosis › with thyroid storm
• Syndrome › myasthenic › in › endocrine disease NEC
• Syndrome › myasthenic › in › neoplastic disease
• Syndrome › myasthenic › in › thyrotoxicosis (hyperthyroidism)
• Syndrome › myasthenic › in › thyrotoxicosis (hyperthyroidism) › with thyroid storm

Nearby codes

• G73 Disorders of myoneural junction and muscle in diseases classified elsewhere
• G73.1 Lambert-Eaton syndrome in neoplastic disease
• G73.3 Myasthenic syndromes in other diseases classified elsewhere (this code)
• G73.7 Myopathy in diseases classified elsewhere