G71.8Other primary disorders of muscles

G71.8 is the ICD-10-CM diagnosis code for other primary disorders of muscles. It belongs to category G71 (primary disorders of muscles), block G70-G73 (diseases of myoneural junction and muscle) and chapter 6 (diseases of the nervous system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within G71, choose G71.8 (Other primary disorders of muscles) only when documentation doesn't support a more specific option: muscular dystrophy (G71.0), myotonic disorders (G71.1), congenital myopathies (G71.2), mitochondrial myopathy, not elsewhere classified (G71.3) and primary disorder of muscle, unspecified (G71.9).

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 091 (Other Disorders of Nervous System with MCC, relative weight 1.7046), DRG 092 (Other Disorders of Nervous System with CC, relative weight 1.0239) and DRG 093 (Other Disorders of Nervous System without CC/MCC, relative weight 0.7783), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 359.89 (other myopathies).