S91.151A (Open bite of right great toe without damage to nail, initial encounter) compared with S91.151S (Open bite of right great toe without damage to nail, sequela), from the official CMS tabular data. S91.151A and S91.151S 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. S91.151A and S91.151S 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.
| S91.151AOpen bite of right great toe without damage to nail, initial encounter | S91.151SOpen bite of right great toe without damage to nail, 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 | Open bite of right great toe without damage to nail, initial encounter is a billable ICD-10-CM diagnosis code (S91.151A). | Open bite of right great toe without damage to nail, sequela is a billable ICD-10-CM diagnosis code (S91.151S). |
| 7th character | The appropriate 7th character is to be added to each code from category S91 | The appropriate 7th character is to be added to each code from category S91 |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources