M21.271 (Flexion deformity, right ankle and toes) compared with M21.279 (Flexion deformity, unspecified ankle and toes), from the official CMS tabular data. M21.271 and M21.279 code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.
Source: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. M21.271 and M21.279 name the same condition on opposite sides of the body.
Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.
| M21.271Flexion deformity, right ankle and toes | M21.279Flexion deformity, unspecified ankle and toes | |
|---|---|---|
| Billing status | Billable | Billable |
| 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 | Flexion deformity, right ankle and toes is a billable ICD-10-CM diagnosis code (M21.271). | Flexion deformity, unspecified ankle and toes is a billable ICD-10-CM diagnosis code (M21.279). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources