T23.549 — Corrosion of first degree of unspecified multiple fingers (nail), including thumb
Is T23.549 billable?
No — T23.549 is a non-billable header code. T23.549 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 3 billable codes beneath T23.549.
Billable codes under this header
- T23.549ACorrosion of first degree of unspecified multiple fingers (nail), including thumb, initial encounter
- T23.549DCorrosion of first degree of unspecified multiple fingers (nail), including thumb, subsequent encounter
- T23.549SCorrosion of first degree of unspecified multiple fingers (nail), including thumb, sequela
T23.549 at a glance
| Code | T23.549 |
|---|---|
| Description | Corrosion of first degree of unspecified multiple fingers (nail), including thumb |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
How is T23.549 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to T23.549. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Corrosion › thumb › multiple sites with fingers › first degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › finger › multiple sites › with thumb › first degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first — inherited from T23.5
The underlying condition below must be sequenced before T23.549. T23.549 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 T23.549 to fully describe the condition. T23.549 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 T23.549 to fully describe the condition. T23.549 is sequenced first.
Use additional code — inherited from T23.5
Report an additional code alongside T23.549 to fully describe the condition. T23.549 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 T23.549, but a patient may have both at the same time. When documentation supports it, T23.549 and the excluded code may both be reported.
What codes fall under T23.549? (3)
- T23.549ACorrosion of first degree of unspecified multiple fingers (nail), including thumb, initial encounter
- T23.549DCorrosion of first degree of unspecified multiple fingers (nail), including thumb, subsequent encounter
- T23.549SCorrosion of first degree of unspecified multiple fingers (nail), including thumb, sequela
How long has T23.549 existed?
T23.549 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.