2026 ICD-10-CM Diagnosis Code T45.621APoisoning by hemostatic drug, accidental (unintentional), initial encounter

ICD-10-CM Codes›S00–T88›T36-T50›T45

ICD-10-CM T45.621A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T45.621A is a billable ICD-10-CM diagnosis code for poisoning by hemostatic drug, accidental (unintentional), 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. Coders also document this condition as accidental aminocaproic acid poisoning. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, accidental/unintentional; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.

Code Identity

ICD-10-CM Code
T45.621A
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by hemostatic drug, accidental (unintentional), initial encounter
Short Description
Poisoning by hemostatic drug, accidental, init
Parent Code
T45.621
Poisoning by hemostatic drug, accidental (unintentional)

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 CodeT45.621APoisoning by hemostatic drug, accidental (unintentional), initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Accidental aminocaproic acid poisoning
  • Poisoning by aminocaproic acid

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 EXT020
External cause codes: intent of injury, accidental/unintentional
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT014
External cause codes: poisoning by drug
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ022
Poisoning by drugs, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Aminocaproates

    amino derivatives of caproic acid. included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the amino caproic acid structure.

  • Aminocaproic Acid

    an antifibrinolytic agent that acts by inhibiting plasminogen activators which have fibrinolytic properties.

  • Aprotinin

    a single-chain polypeptide derived from bovine tissues consisting of 58 amino-acid residues. it is an inhibitor of proteolytic enzymes including chymotrypsin; kallikrein; plasmin; and trypsin. it is used in the treatment of hemorrhage associated with raised plasma concentrations of plasmin. it is also used to reduce blood loss and transfusion requirements in patients at high risk of major blood loss during and following open heart surgery with extracorporeal circulation. (reynolds jef(ed): martindale: the extra pharmacopoeia (electronic version). micromedex, inc, englewood, co, 1995)

  • Tranexamic Acid

    antifibrinolytic hemostatic used in severe hemorrhage.

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
Aminocaproic acidT45.621T45.622T45.623T45.624T45.625T45.626
Antifibrinolytic drugT45.621T45.622T45.623T45.624T45.625T45.626
AprotininT45.621T45.622T45.623T45.624T45.625T45.626
Epsilon amino-caproic acidT45.621T45.622T45.623T45.624T45.625T45.626
HemostaticT45.621T45.622T45.623T45.624T45.625T45.626
Hemostatic::drug, systemicT45.621T45.622T45.623T45.624T45.625T45.626
Tranexamic acidT45.621T45.622T45.623T45.624T45.625T45.626

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 T45.621A to ICD-9-CMHistory

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

ICD-9-CM
964.8 Poisoning-blood agt NEC
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
E858.2 Acc poison-blood agent
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 T45.621AOverview

Is T45.621A (Poisoning by hemostatic drug, accidental (unintentional)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by hemostatic drug, accidental (unintentional), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T45.621A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by hemostatic drug, accidental (unintentional), such as an emergency visit or first evaluation.

What MS-DRG does T45.621A group to?

When poisoning by hemostatic drug, accidental (unintentional), initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T45.621A?

Under the General Equivalence Mappings, poisoning by hemostatic drug, accidental (unintentional), initial encounter converts to ICD-9-CM 964.8 (poisoning-blood agt NEC) and E858.2 (acc poison-blood agent). 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.