G70.81 Lambert-Eaton syndrome in disease classified elsewhere

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

Excludes1 (never code together)

• Lambert-Eaton syndrome in neoplastic disease (G73.1)

Code first

• underlying disease

Applies from G70 Myasthenia gravis and other myoneural disorders

Excludes1 (never code together)

• botulism (A05.1, A48.51-A48.52)
• transient neonatal myasthenia gravis (P94.0)

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)

• 358.39 Lambert-Eaton syndrome in other 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 G70.81

Back-references to G70.81

• Type 1 Excludes: G73.1 Lambert-Eaton syndrome in neoplastic disease ("Lambert-Eaton syndrome not associated with neoplasm (G70.80-G70.81)")

Diagnosis Index entries for G70.81

• Syndrome › Lambert-Eaton › in › specified disease NEC

Nearby codes

• G70.01 Myasthenia gravis with (acute) exacerbation
• G70.1 Toxic myoneural disorders
• G70.2 Congenital and developmental myasthenia
• G70.8 Other specified myoneural disorders
• G70.80 Lambert-Eaton syndrome, unspecified
• G70.81 Lambert-Eaton syndrome in disease classified elsewhere (this code)
• G70.89 Other specified myoneural disorders
• G70.9 Myoneural disorder, unspecified