S09.312A (Primary blast injury of left ear, initial encounter) compared with S09.312S (Primary blast injury of left ear, sequela), from the official CMS tabular data. S09.312A and S09.312S 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. S09.312A and S09.312S 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.
| S09.312APrimary blast injury of left ear, initial encounter | S09.312SPrimary blast injury of left ear, 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 | Primary blast injury of left ear, initial encounter is a billable ICD-10-CM diagnosis code (S09.312A). | Primary blast injury of left ear, sequela is a billable ICD-10-CM diagnosis code (S09.312S). |
| 7th character | The appropriate 7th character is to be added to each code from category S09 | The appropriate 7th character is to be added to each code from category S09 |
| 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