T21.43XA — Corrosion of unspecified degree of upper back, initial encounter
Is T21.43XA billable?
Yes, but T21.43XA is an unspecified code. T21.43XA is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T21.43XA 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 T21.43XA — the more specific alternatives are listed below.
More specific alternatives
- T21.10XABurn of first degree of trunk, unspecified site, initial encounter
- T21.20XABurn of second degree of trunk, unspecified site, initial encounter
- T21.30XABurn of third degree of trunk, unspecified site, initial encounter
- T21.50XACorrosion of first degree of trunk, unspecified site, initial encounter
- T21.60XACorrosion of second degree of trunk, unspecified site, initial encounter
- T21.70XACorrosion of third degree of trunk, unspecified site, initial encounter
T21.43XA at a glance
| Code | T21.43XA |
|---|---|
| Description | Corrosion of unspecified degree of upper back, 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 T21.43XA?
In T21.43XA, the 7th character A means initial encounter. The 7th character is required for T21.43XA to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T21.43XA group to?
T21.43XA 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 T21.43XA listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T21.43, the nearest indexed parent of T21.43XA. Use them to find the family, then select the specific code.
- Corrosion › back › upper (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Inclusion terms
Alternative wording in documentation that is classified to T21.43XA.
- Corrosion of unspecified degree of interscapular region
Code first — inherited from T21.4
The underlying condition below must be sequenced before T21.43XA. T21.43XA 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 T21.43XA to fully describe the condition. T21.43XA 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 T21.43XA to fully describe the condition. T21.43XA is sequenced first.
Use additional code — inherited from T21.4
Report an additional code alongside T21.43XA to fully describe the condition. T21.43XA 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 T21.43XA, but a patient may have both at the same time. When documentation supports it, T21.43XA and the excluded code may both be reported.
Excludes2 — not included here — inherited from T21
The conditions below are not part of T21.43XA, but a patient may have both at the same time. When documentation supports it, T21.43XA and the excluded code may both be reported.
How long has T21.43XA existed?
T21.43XA 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.