T85.850A (Stenosis due to nervous system prosthetic devices, implants and grafts, initial encounter) compared with T85.850S (Stenosis due to nervous system prosthetic devices, implants and grafts, sequela), from the official CMS tabular data. T85.850A and T85.850S 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. T85.850A and T85.850S 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.
| T85.850AStenosis due to nervous system prosthetic devices, implants and grafts, initial encounter | T85.850SStenosis due to nervous system prosthetic devices, implants and grafts, 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 | Stenosis due to nervous system prosthetic devices, implants and grafts, initial encounter is a billable ICD-10-CM diagnosis code (T85.850A). | Stenosis due to nervous system prosthetic devices, implants and grafts, sequela is a billable ICD-10-CM diagnosis code (T85.850S). |
| 7th character | The appropriate 7th character is to be added to each code from category T85 | The appropriate 7th character is to be added to each code from category T85 |
| Use additional code | code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82) | code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources