M35.9
Systemic involvement of connective tissue, unspecified
M35.9 (also written M359) is a billable ICD-10-CM diagnosis code for systemic involvement of connective tissue, unspecified. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 23 codes in category M35 (Other systemic involvement of connective tissue). The Alphabetic Index lists it under 12 entries. Its coding notes include 2 Excludes1 entries and 10 Excludes2 entries.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- reactive perforating collagenosis (L87.1)
Also from chapter/block level (1 note)
- autoimmune disease, single organ or single cell-type -code to relevant condition category
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (10 notes)
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Includes
Further defines or gives examples of the content of the category.
Also from chapter/block level (4 notes)
- autoimmune disease NOS
- collagen (vascular) disease NOS
- systemic autoimmune disease
- systemic collagen (vascular) disease
Inclusion terms
Conditions classified to this code.
- Autoimmune disease (systemic) NOS
- Collagen (vascular) disease NOS
Notes
Also from chapter/block level (1 note)
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 12 entries
- Ataxia, ataxy, ataxic, gluten
- Autoimmune, disease (systemic)
- Collagenosis, collagen disease (nonvascular) (vascular)
- Disease, diseased, autoimmune (systemic) NOS
- Disease, diseased, collagen NOS (nonvascular) (vascular)
- Disease, diseased, connective tissue, systemic (diffuse)
- Disease, diseased, mesenchymal
- Dyscollagenosis
- Polyneuropathy (peripheral), in (due to), collagen vascular disease NEC
- Polyneuropathy (peripheral), in (due to), systemic, connective tissue disorder
- Skin, hidebound
- Syndrome, connective tissue