T25.539A — Corrosion of first degree of unspecified toe(s) (nail), initial encounter
Is T25.539A billable?
Yes, but T25.539A is an unspecified code. T25.539A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T25.539A 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 T25.539A — the more specific alternatives are listed below.
T25.539A at a glance
| Code | T25.539A |
|---|---|
| Description | Corrosion of first degree of unspecified toe(s) (nail), initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in T25.539A?
In T25.539A, the 7th character A means initial encounter. The 7th character is required for T25.539A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T25.539A group to?
T25.539A sits in MDC 22 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 935Non-Extensive Burnsmedical
How is T25.539A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T25.539, the nearest indexed parent of T25.539A. Use them to find the family, then select the specific code.
- Corrosion › toe › first degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first — inherited from T25.5
The underlying condition below must be sequenced before T25.539A. T25.539A 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 T25.539A to fully describe the condition. T25.539A 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 T25.539A to fully describe the condition. T25.539A is sequenced first.
Use additional code — inherited from T25.5
Report an additional code alongside T25.539A to fully describe the condition. T25.539A 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 T25.539A, but a patient may have both at the same time. When documentation supports it, T25.539A and the excluded code may both be reported.
How long has T25.539A existed?
T25.539A 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.