ICD-10 Code G70.2 – Congenital and developmental myasthenia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G70.2 – Congenital and developmental myasthenia
What it is
G70.2 identifies congenital and developmental myasthenia, a group of inherited neuromuscular disorders that cause impaired nerve-to-muscle signaling. It is used when weakness begins early in life and is not due to autoimmune myasthenia gravis.
Clinical signs
Common findings include fluctuating muscle weakness, fatigability, ptosis, and eye movement problems. Clinical features vary; refer to documentation for the specific syndrome, age of onset, and confirmed diagnosis.
When to use this code
Use this code when the record documents congenital or developmental myasthenia, including a hereditary neuromuscular transmission defect. It may appear in childhood evaluations for persistent weakness, abnormal ocular findings, or feeding and motor difficulties. Code only when the diagnosis is clearly stated.
Do not use for
Do not use G70.2 for acquired myasthenia gravis, generalized muscle weakness, or unspecified neuromuscular symptoms. If the provider has not confirmed a congenital or developmental myasthenic disorder, check documentation.
Coding tip
Look for the exact phrase “congenital myasthenia” or a documented hereditary neuromuscular junction disorder before assigning G70.2.