T24.709A — Corrosion of third degree of unspecified site of unspecified lower limb, except ankle and foot, initial encounter
Is T24.709A billable?
Yes, but T24.709A will trip a Medicare edit. T24.709A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists T24.709A under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
More specific alternatives
- T24.711ACorrosion of third degree of right thigh, initial encounter
- T24.721ACorrosion of third degree of right knee, initial encounter
- T24.731ACorrosion of third degree of right lower leg, initial encounter
- T24.791ACorrosion of third degree of multiple sites of right lower limb, except ankle and foot, initial encounter
T24.709A at a glance
| Code | T24.709A |
|---|---|
| Description | Corrosion of third degree of unspecified site of unspecified lower limb, except ankle and foot, 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 T24.709A?
In T24.709A, the 7th character A means initial encounter. The 7th character is required for T24.709A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T24.709A?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T24.709A directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does T24.709A group to?
T24.709A sits in MDC 22 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.
- 927Extensive Burns or Full Thickness Burns with MV >96 Hours with Skin Graftsurgical
- 933Extensive Burns or Full Thickness Burns with MV >96 Hours without Skin Graftmedical
As a secondary diagnosis, T24.709A 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 T24.709A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T24.709, the nearest indexed parent of T24.709A. Use them to find the family, then select the specific code.
- Corrosion › lower › limb › third degree (injury) (acid) (caustic) (chemical) (lime) (external) (internal)
Code first — inherited from T24.7
The underlying condition below must be sequenced before T24.709A. T24.709A 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 T24.709A to fully describe the condition. T24.709A 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 T24.709A to fully describe the condition. T24.709A is sequenced first.
Use additional code — inherited from T24.7
Report an additional code alongside T24.709A to fully describe the condition. T24.709A 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 T24.709A, but a patient may have both at the same time. When documentation supports it, T24.709A and the excluded code may both be reported.
Excludes2 — not included here — inherited from T24
The conditions below are not part of T24.709A, but a patient may have both at the same time. When documentation supports it, T24.709A and the excluded code may both be reported.
How long has T24.709A existed?
T24.709A 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.