M21.171 (Varus deformity, not elsewhere classified, right ankle) compared with M21.172 (Varus deformity, not elsewhere classified, left ankle), from the official CMS tabular data. M21.171 and M21.172 code the same condition on opposite sides. MedCoder-derived
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. M21.171 and M21.172 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.
| M21.171Varus deformity, not elsewhere classified, right ankle | M21.172Varus deformity, not elsewhere classified, left ankle | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the musculoskeletal system and connective tissue | M00-M99 — Diseases of the musculoskeletal system and connective tissue |
| Definition | Varus deformity, not elsewhere classified, right ankle is a billable ICD-10-CM diagnosis code (M21.171). | Varus deformity, not elsewhere classified, left ankle is a billable ICD-10-CM diagnosis code (M21.172). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources