ICD-10 Code G70 – Myasthenia gravis and other myoneural disorders (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G70 – Myasthenia gravis and other myoneural disorders
What it is
G70 identifies myasthenia gravis and related disorders that affect nerve-to-muscle transmission. Use it when the record shows a myoneural disorder causing muscle weakness from impaired neuromuscular signaling.
Clinical signs
Typical findings include fluctuating skeletal muscle weakness, often worse with activity and improved with rest. Clinical features vary; refer to documentation for ocular, bulbar, limb, or respiratory involvement.
When to use this code
Use G70 when the provider documents myasthenia gravis or another myoneural disorder as the diagnosis. It may also fit encounters for evaluation or follow-up of a confirmed condition when the note supports the disorder being present.
Assign the code from the documented diagnosis, not from nonspecific weakness alone. If the record only says “rule out” or gives unclear neuromuscular symptoms, check documentation before coding.
Do not use for
Do not use G70 for generalized muscle weakness, fatigue, or neuropathy without a documented myoneural disorder. Also avoid it when the provider documents a different neuromuscular disease. Check documentation.
Coding tip
Code the specific myoneural diagnosis documented by the provider, and query if the record only describes weakness without a clear diagnosis.