M35.1 – Other overlap syndromes

ICD-10-CM 2027 diagnosis code · Systemic connective tissue disorders

Billable code

ICD-10-CM code M35.1

Code: M35.1 (claims format: M351)
Description: Other overlap syndromes
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 M35.1

Applicable to:

Mixed connective tissue disease

Excludes1 (not coded here):

polyangiitis overlap syndrome (M30.8)

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 M35.1

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in M35

M35.0 – Sjogren syndromeHeader
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
M35.9 – Systemic involvement of connective tissue, unspecifiedBillable

Frequently asked questions

What is ICD-10 code M35.1?

M35.1 is the ICD-10-CM code for other overlap syndromes, in the block M30-M36 (Systemic connective tissue disorders).

Is M35.1 a billable code?

Yes. M35.1 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does M35.1 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.