2026 ICD-10-CM Diagnosis Code T45.523SPoisoning by antithrombotic drugs, assault, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T45

ICD-10-CM T45.523S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T45.523S is a billable ICD-10-CM diagnosis code for poisoning by antithrombotic drugs, assault, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T45.523S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by antithrombotic drugs, assault, sequela
Short Description
Poisoning by antithrombotic drugs, assault, sequela
Same as the full description in the CMS dataset.
Parent Code
T45.523
Poisoning by antithrombotic drugs, assault

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
CategoryT45Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified
This CodeT45.523SPoisoning by antithrombotic drugs, assault, sequela

Present on Admission (POA)Billing

T45.523S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Coding GuidelinesGuidance

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified (T45). 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 Yes · outpatient Yes

Clinical InformationClinical

  • Epoprostenol

    a prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. it is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. the sodium salt has been also used to treat primary pulmonary hypertension (hypertension, pulmonary).

  • Receptors, Epoprostenol

    cell surface receptors for epoprostenol. they are coupled to heterotrimeric g-proteins.

  • Ticlopidine

    an effective inhibitor of platelet aggregation commonly used in the placement of stents in coronary arteries.

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
AntithromboticT45.521T45.522T45.523T45.524T45.525T45.526
EpoprostenolT45.521T45.522T45.523T45.524T45.525T45.526
IndobufenT45.521T45.522T45.523T45.524T45.525T45.526
ProstacyclinT45.521T45.522T45.523T45.524T45.525T45.526
Prostaglandin (I2)T45.521T45.522T45.523T45.524T45.525T45.526
Prostaglandin (I2)::E1T45.521T45.522T45.523T45.524T45.525T45.526
Prostaglandin (I2)::E2T45.521T45.522T45.523T45.524T45.525T45.526
Prostaglandin (I2)::F2 alphaT45.521T45.522T45.523T45.524T45.525T45.526
TiclopidineT45.521T45.522T45.523T45.524T45.525T45.526
TriflusalT45.521T45.522T45.523T45.524T45.525T45.526

Patient EducationClinical

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Read the full article at MedlinePlus

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

Convert T45.523S to ICD-9-CMHistory

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

ICD-9-CM
909.0 Late eff drug poisoning
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
E969 Late effect assault
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 T45.523SOverview

Is T45.523S (Poisoning by antithrombotic drugs, assault) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by antithrombotic drugs, assault, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T45.523S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by antithrombotic drugs, assault itself has resolved, not the original event.

What MS-DRG does T45.523S group to?

When poisoning by antithrombotic drugs, assault, 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 T45.523S 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 poisoning by antithrombotic drugs, assault, sequela on inpatient claims.

What is the ICD-9 equivalent of T45.523S?

Under the General Equivalence Mappings, poisoning by antithrombotic drugs, assault, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E969 (late effect assault). 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.