S90.541A (External constriction, right ankle, initial encounter) compared with S90.549A (External constriction, unspecified ankle, initial encounter), from the official CMS tabular data. S90.541A and S90.549A 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. S90.541A and S90.549A 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.
| S90.541AExternal constriction, right ankle, initial encounter | S90.549AExternal constriction, unspecified ankle, initial encounter | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | External constriction, right ankle, initial encounter is a billable ICD-10-CM diagnosis code (S90.541A). | External constriction, unspecified ankle, initial encounter is a billable ICD-10-CM diagnosis code (S90.549A). |
| 7th character | The appropriate 7th character is to be added to each code from category S90 | The appropriate 7th character is to be added to each code from category S90 |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources