ICD-10-CM 2027 diagnosis code
T24.709ACorrosion of third degree of unspecified site of unspecified lower limb, except ankle and foot, initial encounter
T24.709A is a valid, billable ICD-10-CM code for corrosion of third degree of unspecified site of unspecified lower limb, except ankle and foot, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Corros third deg of unsp site unsp low limb, ex ank/ft, init
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About T24.709A
T24.709A is the ICD-10-CM diagnosis code for corrosion of third degree of unspecified site of unspecified lower limb, except ankle and foot, initial encounter. It belongs to category T24 (burn and corrosion of lower limb, except ankle and foot), block T20-T25 (burns and corrosions of external body surface, specified by site) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 927 (Extensive Burns or Full Thickness Burns with MV >96 Hours with Skin Graft, relative weight 27.846), DRG 933 (Extensive Burns or Full Thickness Burns with MV >96 Hours without Skin Graft, relative weight 3.5048), DRG 928 (Full Thickness Burn with Skin Graft or Inhalation Injury with CC/MCC, relative weight 7.6477), DRG 929 (Full Thickness Burn with Skin Graft or Inhalation Injury without CC/MCC, relative weight 3.0193) and DRG 934 (Full Thickness Burn without Skin Graft or Inhalation Injury, relative weight 1.9895), in MDC 22 (Burns), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It is an unspecified code for which a more specific option (often laterality) exists, and the Medicare Code Editor flags it for review on inpatient claims.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 945.30 (full-thickness skin loss [third degree NOS] of lower limb [leg] unspecified site) and 945.40 (deep necrosis of underlying tissues [deep third degree] without mention of loss of a body part, lower limb [leg], unspecified site).
7th character
Ainitial encounter
CC/MCC status for this injury by encounter: CC for A; Neither CC nor MCC for D, S.
Other encounter types for T24.709:
Notes that apply from higher levels
Instructions written at a parent level also apply to T24.709A.
Broader instructions also apply from T20-T25 Burns and corrosions of external body surface, specified by site and Chapter 19: Injury, poisoning and certain other consequences of external causes.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 22 · Burns
ICD-9-CM equivalent
Converter →- 945.30Full-thickness skin loss [third degree NOS] of lower limb [leg] unspecified siteapproximate
- 945.40Deep necrosis of underlying tissues [deep third degree] without mention of loss of a body part, lower limb [leg], unspecified siteapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about T24.709A
Is T24.709A billable?
- Yes. T24.709A is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
What does the "A" at the end of T24.709A mean?
- It is the 7th character for initial encounter. Per the official guidelines, use it while the patient is receiving active treatment for the condition.
Can T24.709A be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict T24.709A as a principal diagnosis.
Is T24.709A a CC or MCC?
- T24.709A is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does T24.709A group to?
- T24.709A is used in the MS-DRG v44.0 logic for MS-DRG 927 (Extensive Burns or Full Thickness Burns with MV >96 Hours with Skin Graft), MS-DRG 933 (Extensive Burns or Full Thickness Burns with MV >96 Hours without Skin Graft), MS-DRG 928 (Full Thickness Burn with Skin Graft or Inhalation Injury with CC/MCC), MS-DRG 929 (Full Thickness Burn with Skin Graft or Inhalation Injury without CC/MCC) and MS-DRG 934 (Full Thickness Burn without Skin Graft or Inhalation Injury). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for T24.709A?
- The CMS General Equivalence Mappings map T24.709A to ICD-9-CM 945.30 and 945.40.