S86.099A (Other specified injury of unspecified Achilles tendon, initial encounter) compared with S86.099S (Other specified injury of unspecified Achilles tendon, sequela), from the official CMS tabular data. S86.099A and S86.099S 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. S86.099A and S86.099S 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.
| S86.099AOther specified injury of unspecified Achilles tendon, initial encounter | S86.099SOther specified injury of unspecified Achilles tendon, 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 | Other specified injury of unspecified Achilles tendon, initial encounter is a billable ICD-10-CM diagnosis code (S86.099A). | Other specified injury of unspecified Achilles tendon, sequela is a billable ICD-10-CM diagnosis code (S86.099S). |
| 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