S51.801A (Unspecified open wound of right forearm, initial encounter) compared with S51.801D (Unspecified open wound of right forearm, subsequent encounter), from the official CMS tabular data. S51.801A and S51.801D 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. S51.801A and S51.801D 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.
| S51.801AUnspecified open wound of right forearm, initial encounter | S51.801DUnspecified open wound of right forearm, subsequent encounter | |
|---|---|---|
| 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 | Unspecified open wound of right forearm, initial encounter is a billable ICD-10-CM diagnosis code (S51.801A). | Unspecified open wound of right forearm, subsequent encounter is a billable ICD-10-CM diagnosis code (S51.801D). |
| 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