R10.A1 (Flank pain, right side) compared with R10.A2 (Flank pain, left side), from the official CMS tabular data. R10.A1 and R10.A2 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. R10.A1 and R10.A2 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.
| R10.A1Flank pain, right side | R10.A2Flank pain, left side | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) | R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) |
| Definition | Flank pain, right side is a billable ICD-10-CM diagnosis code (R10.A1). | Flank pain, left side is a billable ICD-10-CM diagnosis code (R10.A2). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources