T25.799S — Corrosion of third degree of multiple sites of unspecified ankle and foot, sequela
Is T25.799S billable?
Yes, but T25.799S is an unspecified code. T25.799S is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T25.799S is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting T25.799S — the more specific alternatives are listed below.
T25.799S at a glance
| Code | T25.799S |
|---|---|
| Description | Corrosion of third degree of multiple sites of unspecified ankle and foot, sequela |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "S" | sequela |
What does the 7th character "S" mean in T25.799S?
In T25.799S, the 7th character S means sequela. The 7th character is required for T25.799S to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T25.799S group to?
T25.799S sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 604Trauma to the Skin, Subcutaneous Tissue and Breast with MCCmedical
- 605Trauma to the Skin, Subcutaneous Tissue and Breast without MCCmedical
How is T25.799S listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T25.799, the nearest indexed parent of T25.799S. Use them to find the family, then select the specific code.
- Corrosion › lower › limb › multiple sites, except ankle and foot › ankle and foot › third degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first — inherited from T25.7
The underlying condition below must be sequenced before T25.799S. T25.799S describes a manifestation and cannot be the principal or first-listed diagnosis.
- (T51-T65) to identify chemical and intent
Use additional code — inherited from Chapter 19
Report an additional code alongside T25.799S to fully describe the condition. T25.799S is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T20-T25
Report an additional code alongside T25.799S to fully describe the condition. T25.799S is sequenced first.
Use additional code — inherited from T25.7
Report an additional code alongside T25.799S to fully describe the condition. T25.799S is sequenced first.
- external cause code to identify place (Y92)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T25.799S, but a patient may have both at the same time. When documentation supports it, T25.799S and the excluded code may both be reported.
How long has T25.799S existed?
T25.799S has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.