ICD-10 Code for Myasthenia
The ICD-10-CM code for myasthenia is G70.9 — Myoneural disorder, unspecified. This is the code the Alphabetic Index gives for myasthenia with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
G70.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which myasthenia code should you use?
The Alphabetic Index lists 11 codes under Myasthenia. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
Myasthenia gravis
| with exacerbation | G70.01 | Myasthenia gravis with (acute) exacerbation | |
| in crisis | G70.01 | Myasthenia gravis with (acute) exacerbation | |
| neonatal, transient | P94.0 | Transient neonatal myasthenia gravis | |
| pseudoparalytica | G70.00 | Myasthenia gravis without (acute) exacerbation | |
| pseudoparalytica › with exacerbation | G70.01 | Myasthenia gravis with (acute) exacerbation | |
| pseudoparalytica › in crisis | G70.01 | Myasthenia gravis with (acute) exacerbation |
Myasthenia syndrome
| in › neoplastic disease | D49.9 | Neoplasm of unspecified behavior of unspecified site | |
| in › pernicious anemia | D51.0 | Vitamin B12 deficiency anemia due to intrinsic factor deficiency | |
| in › thyrotoxicosis | E05.90 | Thyrotoxicosis, unspecified without thyrotoxic crisis or storm | |
| in › thyrotoxicosis › with thyroid storm | E05.91 | Thyrotoxicosis, unspecified with thyrotoxic crisis or storm |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources