T85.79XA vs T85.79XS

T85.79XA (Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, initial encounter) compared with T85.79XS (Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, sequela), from the official CMS tabular data. T85.79XA and T85.79XS code the same injury at a different phase of treatment. MedCoder-derived

Relationship

Review

Encounter relationship

T85.79XA

Initial encounter

Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, initial encounter

↔

T85.79XS

Sequela

Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, sequela

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

Can these codes be reported together?

Same injury, other encounter phase. T85.79XA and T85.79XS 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.

Side by side

	T85.79XAInfection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, initial encounter	T85.79XSInfection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, sequela
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	Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, initial encounter is a billable ICD-10-CM diagnosis code (T85.79A).	Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts, sequela is a billable ICD-10-CM diagnosis code (T85.79S).
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 to identify infection 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 infection 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

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources