M90.522Osteonecrosis in diseases classified elsewhere, left upper arm

M90.522 is the ICD-10-CM diagnosis code for osteonecrosis in diseases classified elsewhere, left upper arm. It belongs to category M90 (Osteopathies in diseases classified elsewhere), block M86-M90 (other osteopathies) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within M90.52 (osteonecrosis in diseases classified elsewhere, upper arm), M90.522 is specifically for osteonecrosis in diseases classified elsewhere, left upper arm. Related codes cover right upper arm (M90.521) and unspecified upper arm (M90.529).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 553 (Bone Diseases and Arthropathies with MCC, relative weight 1.2494) and DRG 554 (Bone Diseases and Arthropathies without MCC, relative weight 0.8331), 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.

It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

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 731.8 (other bone involvement in diseases classified elsewhere) and 733.49 (aseptic necrosis of bone, other).