2026 ICD-10-CM Diagnosis Code T48.0X6AUnderdosing of oxytocic drugs, initial encounter

ICD-10-CM CodesS00–T88T36-T50T48

ICD-10-CM T48.0X6A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T48.0X6A is a billable ICD-10-CM diagnosis code for underdosing 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). 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 Underdosing of drugs and medicaments, initial encounter.

Code Identity

ICD-10-CM Code
T48.0X6A
Billable Status
Yes — Valid for Submission
Code Describes
Underdosing of oxytocic drugs, initial encounter
Short Description
Underdosing of oxytocic drugs, initial encounter
Same as the full description in the CMS dataset.
Parent Code
Underdosing 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 CodeT48.0X6AUnderdosing of oxytocic drugs, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T48.0X6A.

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.

Coding GuidelinesGuidance

Underdosing refers to taking less of a medication than is prescribed by a provider or a manufacturer's instruction. Codes for underdosing should never be assigned as principal or first-listed codes. If a patient has a relapse or exacerbation of the medical condition for which the drug is prescribed because of the reduction in dose, then the medical condition itself should be coded.

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 INJ029
Underdosing of drugs and medicaments, initial encounter
Default principal diagnosis: inpatient No · outpatient No

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

Medication Errors

Medicines treat infectious diseases, prevent problems from chronic diseases, and ease pain. But medicines can also cause harmful reactions if not used correctly. Errors can happen in the hospital, at the health care provider's office, at the pharmacy, or at home. You can help prevent errors by:

Read the full article at MedlinePlus

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

Convert T48.0X6A to ICD-9-CMHistory

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

ICD-9-CM
No Map There is no ICD-9 equivalent for this code.

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 T48.0X6AOverview

Is T48.0X6A (Underdosing of oxytocic drugs) a billable code?

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

What does the 7th character A in T48.0X6A mean?

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

Can T48.0X6A be a principal diagnosis?

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

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.