ICD-10 Code G70.80 – Lambert-Eaton Syndrome, Unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G70.80 – Lambert-Eaton syndrome, unspecified
What it is
G70.80 identifies Lambert-Eaton syndrome when the documentation does not specify a subtype. It refers to a neuromuscular junction disorder that causes impaired muscle activation.
Clinical signs
Common findings include proximal muscle weakness, reduced reflexes, and possible autonomic symptoms such as dry mouth. Clinical features vary; refer to documentation.
When to use this code
Use G70.80 when the provider documents Lambert-Eaton syndrome but does not identify a more specific form. It may also apply when the record confirms the diagnosis without further detail. Make sure the note supports a neuromuscular junction disorder rather than another cause of weakness.
Do not use for
Do not use this code for myasthenia gravis or other unspecified generalized weakness. If the documentation names a different neuromuscular condition, code that diagnosis instead.
Coding tip
Query the provider if Lambert-Eaton syndrome is mentioned but the record is unclear about specificity.