T28.5XXA — Corrosion of mouth and pharynx, initial encounter
Is T28.5XXA billable?
Yes — T28.5XXA is billable for FY2027. T28.5XXA is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T28.5XXA may be submitted for encounters from October 1, 2026 through September 30, 2027.
T28.5XXA at a glance
| Code | T28.5XXA |
|---|---|
| Description | Corrosion of mouth and pharynx, 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 T28.5XXA?
In T28.5XXA, the 7th character A means initial encounter. The 7th character is required for T28.5XXA to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T28.5XXA group to?
T28.5XXA sits in MDC Pre and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 011Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCCsurgical
- 012Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CCsurgical
- 013Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCCsurgical
How is T28.5XXA listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T28.5, the nearest indexed parent of T28.5XXA. Use them to find the family, then select the specific code.
- Corrosion › mouth (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › pharynx (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › throat (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › tongue (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › tonsil (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › internal organ › mouth (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › internal organ › pharynx (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first
The underlying condition below must be sequenced before T28.5XXA. T28.5XXA describes a manifestation and cannot be the principal or first-listed diagnosis.
- (T51-T65) to identify chemical and intent
Code first — inherited from T28.5
The underlying condition below must be sequenced before T28.5XXA. T28.5XXA 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 T28.5XXA to fully describe the condition. T28.5XXA is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T28
Report an additional code alongside T28.5XXA to fully describe the condition. T28.5XXA is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T28.5XXA, but a patient may have both at the same time. When documentation supports it, T28.5XXA and the excluded code may both be reported.
How long has T28.5XXA existed?
T28.5XXA 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.