ICD-10 code for muscle calcification

The ICD-10-CM code for muscle calcification is M61.9 (Calcification and ossification of muscle, unspecified). The official index lists 12 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on M61.9.

Within M61, choose M61.9 (unspecified) only when documentation doesn't support a more specific option: myositis ossificans traumatica (M61.0), myositis ossificans progressiva (M61.1), paralytic calcification and ossification of muscle (M61.2), s associated with burns (M61.3), other calcification of muscle (M61.4) and other ossification of muscle (M61.5).

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.