M35.8Other specified systemic involvement of connective tissue

M35.8 is the ICD-10-CM diagnosis code for other specified systemic involvement of connective tissue. It belongs to category M35 (other systemic involvement of connective tissue), block M30-M36 (systemic connective tissue disorders) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within M35, choose M35.8 (Other specified systemic involvement of connective tissue) only when documentation doesn't support a more specific option: Sjogren syndrome (M35.0), other overlap syndromes (M35.1), Behcet's disease (M35.2), polymyalgia rheumatica (M35.3), diffuse (eosinophilic) fasciitis (M35.4), multifocal fibrosclerosis (M35.5), relapsing panniculitis [Weber-Christian] (M35.6), hypermobility syndrome (M35.7) and 1 more.

To report this condition, pick the subcode that matches the documentation: M35.81 (syndrome) and M35.89 (tissue).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2021 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 710.5 (eosinophilia myalgia syndrome) and 710.8 (other specified diffuse diseases of connective tissue).