S51.851A (Open bite of right forearm, initial encounter) compared with S51.851S (Open bite of right forearm, sequela), from the official CMS tabular data. S51.851A and S51.851S code the same injury at a different phase of treatment. MedCoder-derived
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. S51.851A and S51.851S 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.
| S51.851AOpen bite of right forearm, initial encounter | S51.851SOpen bite of right forearm, sequela | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | S00-T88 — Injury, poisoning and certain other consequences of external causes | S00-T88 — Injury, poisoning and certain other consequences of external causes |
| Definition | Open bite of right forearm, initial encounter is a billable ICD-10-CM diagnosis code (S51.851A). | Open bite of right forearm, sequela is a billable ICD-10-CM diagnosis code (S51.851S). |
| 7th character | The appropriate 7th character is to be added to each code from category S51 | The appropriate 7th character is to be added to each code from category S51 |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources