2026 ICD-10-CM Diagnosis Code T41.45XSAdverse effect of unspecified anesthetic, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T41

ICD-10-CM T41.45XS
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T41.45XS is a billable ICD-10-CM diagnosis code for adverse effect of unspecified anesthetic, 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 not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T41.45XS
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of unspecified anesthetic, sequela
Short Description
Adverse effect of unspecified anesthetic, sequela
Same as the full description in the CMS dataset.
Parent Code
T41.45
Adverse effect of unspecified anesthetic

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT41Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases
This CodeT41.45XSAdverse effect of unspecified anesthetic, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T41.45XS.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

T41.45XS 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.

  • Adverse anesthesia outcome
  • Adverse reaction to anesthetic agent during dental procedure
  • Allergic reaction caused by anesthetic
  • Anaphylaxis caused by anesthetic
  • Anesthetics adverse reaction
  • Complication of anesthesia
  • Dream disorder
  • Dreaming/nightmare under general anesthesia
  • Drug-induced anaphylaxis
  • Drug-induced hyperpyrexia
  • Hyperpyrexia
  • Hypothermia
  • Hypothermia caused by anesthetic
  • Hypothermia not associated with low environmental temperature
  • Malignant hyperthermia
  • Malignant hyperthermia caused by anesthetic
  • Nausea and vomiting
  • Nausea and vomiting following administration of anesthetic agent
  • Postanesthesia apnea
  • Shock due to anesthesia

Coding GuidelinesGuidance

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases (T41). 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.

CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient Yes

Clinical InformationClinical

  • Malignant Hyperthermia

    rapid and excessive rise of temperature accompanied by muscular rigidity following general anesthesia.

  • Hyperpyrexia

    body temperature of 106 degrees fahrenheit (41.1 degrees celsius) or higher.

  • Malignant Hyperthermia Syndrome|Malignant Hyperpyrexia|Malignant Hyperthermia|Malignant Hyperthermia

    a rare disorder characterized by rapid rise of the body temperature, accompanied by rhabdomyolysis and, if untreated, by collapse and death. it occurs in susceptible individuals who receive certain drugs for general anesthesia, gas anesthetics, or succinylcholine. it may be inherited in an autosomal dominant pattern.

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect		Under­dosing
Anesthetic NEC [See Also: Anesthesia]T41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::with muscle relaxantT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::with muscle relaxant::generalT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::with muscle relaxant::localT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::gaseous NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::general NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::halogenated hydrocarbon derivatives NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::infiltration NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::intravenous NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::local NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::rectalT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::rectal::generalT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::rectal::localT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::regional NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::spinal NECT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::thiobarbiturateT41.41T41.42T41.43T41.44T41.45T41.46
Anesthetic NEC [See Also: Anesthesia]::topicalT41.41T41.42T41.43T41.44T41.45T41.46

Patient EducationClinical

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

The full article covers:

  • What is a drug interaction?
  • What are side effects?
  • What are drug allergies?
  • How can I stay safe when taking medicines?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T41.45XS to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
909.5 Lte efct advrs efct drug
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E938.9 Adv eff loc anes NEC/NOS
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T41.45XSOverview

Is T41.45XS (Adverse effect of unspecified anesthetic) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of unspecified anesthetic, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T41.45XS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of unspecified anesthetic itself has resolved, not the original event.

What MS-DRG does T41.45XS group to?

On inpatient claims, adverse effect of unspecified anesthetic, sequela maps to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T41.45XS be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of unspecified anesthetic, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is T41.45XS 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 adverse effect of unspecified anesthetic, sequela on inpatient claims.

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.