T23.521A — Corrosion of first degree of single right finger (nail) except thumb, initial encounter
Is T23.521A billable?
Yes — T23.521A is billable for FY2027. T23.521A is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T23.521A may be submitted for encounters from October 1, 2026 through September 30, 2027.
T23.521A at a glance
| Code | T23.521A |
|---|---|
| Description | Corrosion of first degree of single right finger (nail) except thumb, 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 T23.521A?
In T23.521A, the 7th character A means initial encounter. The 7th character is required for T23.521A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T23.521A group to?
T23.521A 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 T23.521A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T23.521, the nearest indexed parent of T23.521A. Use them to find the family, then select the specific code.
- Corrosion › finger › right › first degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first — inherited from T23.5
The underlying condition below must be sequenced before T23.521A. T23.521A 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 T23.521A to fully describe the condition. T23.521A 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 T23.521A to fully describe the condition. T23.521A is sequenced first.
Use additional code — inherited from T23.5
Report an additional code alongside T23.521A to fully describe the condition. T23.521A 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 T23.521A, but a patient may have both at the same time. When documentation supports it, T23.521A and the excluded code may both be reported.
How long has T23.521A existed?
T23.521A 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.