S86.912A (Strain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, initial encounter) compared with S86.912S (Strain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, sequela), from the official CMS tabular data. S86.912A and S86.912S 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. S86.912A and S86.912S 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.
| S86.912AStrain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, initial encounter | S86.912SStrain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, 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 | Strain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, initial encounter is a billable ICD-10-CM diagnosis code (S86.912A). | Strain of unspecified muscle(s) and tendon(s) at lower leg level, left leg, sequela is a billable ICD-10-CM diagnosis code (S86.912S). |
| 7th character | The appropriate 7th character is to be added to each code from category S86 | The appropriate 7th character is to be added to each code from category S86 |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources