T21.55XS — Corrosion of first degree of buttock, sequela
Is T21.55XS billable?
Yes — T21.55XS is billable for FY2027. T21.55XS is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T21.55XS may be submitted for encounters from October 1, 2026 through September 30, 2027.
T21.55XS at a glance
| Code | T21.55XS |
|---|---|
| Description | Corrosion of first degree of buttock, 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 T21.55XS?
In T21.55XS, the 7th character S means sequela. The 7th character is required for T21.55XS to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T21.55XS group to?
T21.55XS 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 T21.55XS listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T21.55, the nearest indexed parent of T21.55XS. Use them to find the family, then select the specific code.
- Corrosion › buttock › first degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Inclusion terms
Alternative wording in documentation that is classified to T21.55XS.
- Corrosion of first degree of anus
Code first — inherited from T21.5
The underlying condition below must be sequenced before T21.55XS. T21.55XS 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 T21.55XS to fully describe the condition. T21.55XS 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 T21.55XS to fully describe the condition. T21.55XS is sequenced first.
Use additional code — inherited from T21.5
Report an additional code alongside T21.55XS to fully describe the condition. T21.55XS 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 T21.55XS, but a patient may have both at the same time. When documentation supports it, T21.55XS and the excluded code may both be reported.
Excludes2 — not included here — inherited from T21
The conditions below are not part of T21.55XS, but a patient may have both at the same time. When documentation supports it, T21.55XS and the excluded code may both be reported.
How long has T21.55XS existed?
T21.55XS 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.