T27.4XXA — Corrosion of larynx and trachea, initial encounter
Is T27.4XXA billable?
Yes — T27.4XXA is billable for FY2027. T27.4XXA is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T27.4XXA may be submitted for encounters from October 1, 2026 through September 30, 2027.
T27.4XXA at a glance
| Code | T27.4XXA |
|---|---|
| Description | Corrosion of larynx and trachea, 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 T27.4XXA?
In T27.4XXA, the 7th character A means initial encounter. The 7th character is required for T27.4XXA to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T27.4XXA group to?
T27.4XXA sits in MDC 04 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.
- 205Other Respiratory System Diagnoses with MCCmedical
- 206Other Respiratory System Diagnoses without MCCmedical
As a secondary diagnosis, T27.4XXA is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG. It also carries Hospital-Acquired Condition category 05.
How is T27.4XXA listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T27.4, the nearest indexed parent of T27.4XXA. Use them to find the family, then select the specific code.
- Corrosion › epiglottis (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › larynx (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
- Corrosion › trachea (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first
The underlying condition below must be sequenced before T27.4XXA. T27.4XXA describes a manifestation and cannot be the principal or first-listed diagnosis.
- (T51-T65) to identify chemical and intent
Code first — inherited from T27.4
The underlying condition below must be sequenced before T27.4XXA. T27.4XXA 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 T27.4XXA to fully describe the condition. T27.4XXA is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T27
Report an additional code alongside T27.4XXA to fully describe the condition. T27.4XXA is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T27.4XXA, but a patient may have both at the same time. When documentation supports it, T27.4XXA and the excluded code may both be reported.
How long has T27.4XXA existed?
T27.4XXA 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.