2026 ICD-10-CM Diagnosis Code T48.0X5AAdverse effect of oxytocic drugs, initial encounter

ICD-10-CM CodesS00–T88T36-T50T48

ICD-10-CM T48.0X5A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T48.0X5A is a billable ICD-10-CM diagnosis code for adverse effect of oxytocic drugs, 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 917 through 918. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Adverse effects of drugs and medicaments, initial encounter.

Code Identity

ICD-10-CM Code
T48.0X5A
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of oxytocic drugs, initial encounter
Short Description
Adverse effect of oxytocic drugs, initial encounter
Same as the full description in the CMS dataset.
Parent Code
Adverse effect of oxytocic drugs

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
CategoryT48Poisoning by, adverse effect of and underdosing of agents primarily acting on smooth and skeletal muscles and the respiratory system
This CodeT48.0X5AAdverse effect of oxytocic drugs, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T48.0X5A.

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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adverse reaction to ergometrine and/or oxytocin
  • Adverse reaction to oxytocic agents
  • Adverse reaction to posterior pituitary hormones
  • Carboprost adverse reaction
  • Dinoprost adverse reaction
  • Dinoprostone adverse reaction
  • E series prostaglandin adverse reaction
  • Ergoline drug adverse reaction
  • Ergometrine adverse reaction
  • Ergot alkaloid adverse reaction
  • F series prostaglandin adverse reaction
  • Fetal distress - in labor
  • Fetal distress due to augmentation of labor with oxytocin
  • Gemeprost adverse reaction
  • Oxytocin adverse reaction

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 agents primarily acting on smooth and skeletal muscles and the respiratory system (T48). 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 INJ028
Adverse effects of drugs and medicaments, initial encounter
Default principal diagnosis: inpatient No · outpatient Yes

Clinical InformationClinical

  • Carboprost

    a nonsteroidal abortifacient agent that is effective in both the first and second trimesters of pregnancy.
  • Dinoprost

    a naturally occurring prostaglandin that has oxytocic, luteolytic, and abortifacient activities. due to its vasocontractile properties, the compound has a variety of other biological actions.
  • Dinoprostone

    the most common and most biologically active of the mammalian prostaglandins. it exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. the compound also displays a protective effect on the intestinal mucosa.
  • Ergonovine

    an ergot alkaloid (ergot alkaloids) with uterine and vascular smooth muscle contractile properties.
  • Methylergonovine

    a homolog of ergonovine containing one more ch2 group. (merck index, 11th ed)
  • Cytochrome P-450 CYP2D6

    a cytochrome p450 enzyme that catalyzes the hydroxylation of many drugs and environmental chemicals, such as debrisoquine; adrenergic receptor antagonists; and tricyclic antidepressants. this enzyme is deficient in up to 10 percent of the caucasian population.
  • Sparteine

    a quinolizidine alkaloid isolated from several fabaceae including lupinus; spartium; and cytisus. it has been used as an oxytocic and an anti-arrhythmia agent. it has also been of interest as an indicator of cyp2d6 genotype.

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.

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 T48.0X5A to ICD-9-CMHistory

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

ICD-9-CM
995.29 Adv eff med/biol NEC/NOS
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
E945.0 Adv eff oxytocic agents
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 T48.0X5AOverview

Is T48.0X5A (Adverse effect of oxytocic drugs) a billable code?

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

What does the 7th character A in T48.0X5A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for adverse effect of oxytocic drugs, such as an emergency visit or first evaluation.

What MS-DRG does T48.0X5A group to?

On inpatient claims, adverse effect of oxytocic drugs, initial encounter maps to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T48.0X5A be a principal diagnosis?

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

What is the ICD-9 equivalent of T48.0X5A?

Under the General Equivalence Mappings, adverse effect of oxytocic drugs, initial encounter converts to ICD-9-CM 995.29 (adv eff med/biol NEC/NOS) and E945.0 (adv eff oxytocic agents). 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.