M33.1 – Other dermatomyositis
ICD-10-CM 2027 diagnosis code · Systemic connective tissue disorders
ICD-10-CM code
M33.1
- Code
M33.1(claims format:M331)- Description
- Other dermatomyositis
- Billable
- No – use a more specific code below
- 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
- M33
Billable codes under M33.1
M33.1 is a header code and cannot be used on claims. Choose the most specific code:
- M33.10 – Other dermatomyositis, organ involvement unspecifiedBillable
- M33.11 – Other dermatomyositis with respiratory involvementBillable
- M33.12 – Other dermatomyositis with myopathyBillable
- M33.13 – Other dermatomyositis without myopathyBillable
- M33.19 – Other dermatomyositis with other organ involvementBillable
Notes for M33.1
Applicable to:
- Adult dermatomyositis
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
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
Related codes in M33
Frequently asked questions
What is ICD-10 code M33.1?
M33.1 is the ICD-10-CM code for other dermatomyositis, in the block M30-M36 (Systemic connective tissue disorders).
Is M33.1 a billable code?
No. M33.1 is a header code with more specific child codes; report one of the billable codes listed above.
What category does M33.1 belong to?
It belongs to category M33 – Dermatopolymyositis.
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.