G90.521 (Complex regional pain syndrome I of right lower limb) compared with G90.522 (Complex regional pain syndrome I of left lower limb), from the official CMS tabular data. G90.521 and G90.522 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. G90.521 and G90.522 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.
| G90.521Complex regional pain syndrome I of right lower limb | G90.522Complex regional pain syndrome I of left lower limb | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | G00-G99 — Diseases of the Nervous System (G00-G99) | G00-G99 — Diseases of the Nervous System (G00-G99) |
| Definition | Complex regional pain syndrome I of right lower limb is a billable ICD-10-CM diagnosis code (G90.521). | Complex regional pain syndrome I of left lower limb is a billable ICD-10-CM diagnosis code (G90.522). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources