ICD-10-CM 2027
ICD-10 code for Amyotonia
From the official ICD-10-CM alphabetic index entry “Amyotonia”. Page updated September 29, 2026.
About coding Amyotonia
The ICD-10-CM code for Amyotonia is M62.89 (Other specified disorders of muscle). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on M62.89.
Within M62.8, choose M62.89 (Other specified disorders of muscle) only when documentation doesn't support a more specific option: muscle weakness (generalized) (M62.81), Rhabdomyolysis (M62.82), muscle spasm (M62.83), Sarcopenia (M62.84) and dysfunction of the multifidus muscles, lumbar region (M62.85).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 557 (Tendonitis, Myositis and Bursitis with MCC, relative weight 1.489) and DRG 558 (Tendonitis, Myositis and Bursitis without MCC, relative weight 0.8875), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific Amyotonia codes (official index)
- congenita G70.2 — Congenital and developmental myasthenia
Common questions about Amyotonia ICD-10 codes
What is the ICD-10 code for Amyotonia?
- M62.89 — Other specified disorders of muscle. More specific codes apply when the documentation supports them: G70.2.
What is the ICD-10 code for congenita amyotonia?
- G70.2 — Congenital and developmental myasthenia.
Is M62.89 billable?
- Yes. M62.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M62.89 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M62.89 as a principal diagnosis.
Is M62.89 a CC or MCC?
- No. M62.89 is neither a CC nor an MCC under MS-DRG v44.0.