2026 ICD-10-CM Diagnosis Code T88.51XAHypothermia following anesthesia, initial encounter
T88.51XA is a billable ICD-10-CM diagnosis code for hypothermia following anesthesia, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. 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. Coders also document this condition as hypothermia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Hypothermia
- Hypothermia caused by anesthetic
- Hypothermia not associated with low environmental temperature
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Other complications of surgical and medical care, not elsewhere classified (T88). 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.
Patient EducationClinical
Anesthesia
Anesthesia is the use of medicines, called anesthetics, to prevent pain during surgery and other medical procedures. Medicine may be given by injection, inhalation, topical lotion, spray, eye drops, or a skin patch.
The full article covers:
- What is anesthesia?
- What is anesthesia used for?
- What are the types of anesthesia?
- What are the risks of anesthesia?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T88.51XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T88.51XAOverview
Is T88.51XA (Hypothermia following anesthesia) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report hypothermia following anesthesia, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T88.51XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for hypothermia following anesthesia, such as an emergency visit or first evaluation.
What MS-DRG does T88.51XA group to?
When hypothermia following anesthesia, initial encounter 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.
What is the ICD-9 equivalent of T88.51XA?
Under the General Equivalence Mappings, hypothermia following anesthesia, initial encounter converts to ICD-9-CM 995.89 (adverse effect NEC). 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.
