M21.371 (Foot drop, right foot) compared with M21.372 (Foot drop, left foot), from the official CMS tabular data. M21.371 and M21.372 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. M21.371 and M21.372 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.
| M21.371Foot drop, right foot | M21.372Foot drop, left foot | |
|---|---|---|
| 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 | Foot drop, right foot is a billable ICD-10-CM diagnosis code (M21.371). | Foot drop, left foot is a billable ICD-10-CM diagnosis code (M21.372). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources