M33 vs M63
M33 (Dermatopolymyositis) compared with M63 (Disorders of muscle in diseases classified elsewhere), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. M63 carries an Excludes1 note covering M33: “dermatopolymyositis (M33.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| M33Dermatopolymyositis | M63Disorders of muscle in diseases classified elsewhere | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Dermatopolymyositis is a non-billable ICD-10-CM category code (M33). | Disorders of muscle in diseases classified elsewhere is a non-billable ICD-10-CM category code (M63). |
| Includes | autoimmune disease NOS collagen (vascular) disease NOS systemic autoimmune disease systemic collagen (vascular) disease | — |
| Code first | — | underlying disease, such as: leprosy (A30.-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources