M35.9 – Systemic involvement of connective tissue, unspecified
ICD-10-CM 2027 diagnosis code · Systemic connective tissue disorders
ICD-10-CM code
M35.9
- Code
M35.9(claims format:M359)- Description
- Systemic involvement of connective tissue, unspecified
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
- Block
- M30-M36 Systemic connective tissue disorders
- Parent codes
- M35
Notes for M35.9
Applicable to:
- Autoimmune disease (systemic) NOS
- Collagen (vascular) disease NOS
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
M35 – Other systemic involvement of connective tissue
Excludes1 (not coded here):
- reactive perforating collagenosis (L87.1)
Block M30-M36
Includes:
- autoimmune disease NOS
- collagen (vascular) disease NOS
- systemic autoimmune disease
- systemic collagen (vascular) disease
Excludes1 (not coded here):
- autoimmune disease, single organ or single cell-type -code to relevant condition category
Index terms for M35.9
Entries in the ICD-10-CM alphabetic index that lead to this code:
- Dyscollagenosis
- Skin, hidebound
- Autoimmune, disease
- Syndrome, connective tissue
- Ataxia, ataxy, ataxic, gluten
- Disease, diseased, autoimmune
- Collagenosis, collagen disease
- Disease, diseased, mesenchymal
- Disease, diseased, collagen NOS
- Disease, diseased, connective tissue, systemic
- Polyneuropathy, in, collagen vascular disease NEC
- Polyneuropathy, in, systemic, connective tissue disorder
Related codes in M35
- M35.0 – Sjogren syndromeHeader
- M35.1 – Other overlap syndromesBillable
- M35.2 – Behcet's diseaseBillable
- M35.3 – Polymyalgia rheumaticaBillable
- M35.4 – Diffuse (eosinophilic) fasciitisBillable
- M35.5 – Multifocal fibrosclerosisBillable
- M35.6 – Relapsing panniculitis [Weber-Christian]Billable
- M35.7 – Hypermobility syndromeBillable
- M35.8 – Other specified systemic involvement of connective tissueHeader
Frequently asked questions
What is ICD-10 code M35.9?
M35.9 is the ICD-10-CM code for systemic involvement of connective tissue, unspecified, in the block M30-M36 (Systemic connective tissue disorders).
Is M35.9 a billable code?
Yes. M35.9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
What category does M35.9 belong to?
It belongs to category M35 – Other systemic involvement of connective tissue.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.