S01.90XA (Unspecified open wound of unspecified part of head, initial encounter) compared with S01.90XS (Unspecified open wound of unspecified part of head, sequela), from the official CMS tabular data. S01.90XA and S01.90XS code the same injury at a different phase of treatment.
Same underlying diagnosis, different encounter phase.
The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.
Source: ICD-10-CM Official Guidelines, Section I.C.19.a
Same injury, other encounter phase. S01.90XA and S01.90XS code the same injury at a different phase of treatment, set by the 7th character.
The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.
| S01.90XAUnspecified open wound of unspecified part of head, initial encounter | S01.90XSUnspecified open wound of unspecified part of head, sequela | |
|---|---|---|
| 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 | Unspecified open wound of unspecified part of head, initial encounter is a billable ICD-10-CM diagnosis code (S01.90A). | Unspecified open wound of unspecified part of head, sequela is a billable ICD-10-CM diagnosis code (S01.90S). |
| 7th character | The appropriate 7th character is to be added to each code from category S01 | The appropriate 7th character is to be added to each code from category S01 |
| Includes | injuries of ear injuries of eye injuries of face [any part] injuries of gum | injuries of ear injuries of eye injuries of face [any part] injuries of gum |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources