2026 ICD-10-CM Diagnosis Code T69.021SImmersion foot, right foot, sequela
T69.021S is a billable ICD-10-CM diagnosis code for immersion foot, right foot, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. Coders also document this condition as immersion foot. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Effect of other external causes, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T69.021S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Immersion foot
- Right trench foot
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Other effects of reduced temperature (T69). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Immersion Foot
a condition of the feet produced by prolonged exposure of the feet to water. exposure for 48 hours or more to warm water causes tropical immersion foot or warm-water immersion foot common in vietnam where troops were exposed to prolonged or repeated wading in paddy fields or streams. trench foot results from prolonged exposure to cold, without actual freezing. it was common in trench warfare during world war i, when soldiers stood, sometimes for hours, in trenches with a few inches of cold water in them. (andrews' diseases of the skin, 8th ed, p27)
Patient EducationClinical
Hypothermia
Cold weather can affect your body in different ways. You can get frostbite, which is an injury to the body that is caused by freezing. Your body can also lose heat faster than you can produce it. That can cause hypothermia, or abnormally low body temperature. It can make you sleepy, confused, and clumsy.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T69.021S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T69.021SOverview
Is T69.021S (Immersion foot, right foot) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report immersion foot, right foot, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T69.021S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the immersion foot, right foot itself has resolved, not the original event.
What MS-DRG does T69.021S group to?
When immersion foot, right foot, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T69.021S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for immersion foot, right foot, sequela on inpatient claims.
What is the ICD-9 equivalent of T69.021S?
Under the General Equivalence Mappings, immersion foot, right foot, sequela converts to ICD-9-CM 909.4 (late eff cert ext cause). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
