2026 ICD-10-CM Diagnosis Code T39.2X1APoisoning by pyrazolone derivatives, accidental (unintentional), initial encounter
T39.2X1A is a billable ICD-10-CM diagnosis code for poisoning by pyrazolone derivatives, 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. 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
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Accidental azapropazone overdose
- Accidental azapropazone poisoning
- Accidental dichloralphenazone poisoning
- Accidental oxyphenbutazone overdose
- Accidental oxyphenbutazone poisoning
- Accidental phenylbutazone overdose
- Accidental poisoning by aminophenazone
- Accidental poisoning by phenylbutazone
- Accidental poisoning by pyrazole derivatives
- Aminophenazone poisoning
- Azapropazone overdose
- Azapropazone poisoning
- Dichloralphenazone poisoning
- Oxyphenbutazone overdose
- Oxyphenbutazone poisoning
- Phenylbutazone overdose
- Poisoning by phenylbutazone
- Pyrazole derivative poisoning
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 nonopioid analgesics, antipyretics and antirheumatics (T39). 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.
Clinical InformationClinical
Aminopyrine
a pyrazolone with analgesic, anti-inflammatory, and antipyretic properties but has risk of agranulocytosis. a breath test with 13c-labeled aminopyrine has been used as a non-invasive measure of cytochrome p-450 metabolic activity in liver function tests.Aminopyrine N-Demethylase
a pyrazolone with analgesic, anti-inflammatory, and antipyretic properties but has risk of agranulocytosis. a breath test with 13c-labeled aminopyrine has been used as a non-invasive measure of cytochrome p-450 metabolic activity in liver function tests.Antipyrine
an analgesic and antipyretic that has been given by mouth and as ear drops. antipyrine is often used in testing the effects of other drugs or diseases on drug-metabolizing enzymes in the liver. (from martindale, the extra pharmacopoeia, 30th ed, p29)Dipyrone
a drug that has analgesic, anti-inflammatory, and antipyretic properties. it is the sodium sulfonate of aminopyrine.Feprazone
a pyrazole that has analgesic, anti-inflammatory, and antipyretic properties. it has been used in mild to moderate pain, fever, and inflammation associated with musculoskeletal and joint disorders. (from martindale, the extra pharmacopoeia, 30th ed, p15)Oxyphenbutazone
a non-steroidal anti-inflammatory drug. oxyphenbutazone eyedrops have been used abroad in the management of postoperative ocular inflammation, superficial eye injuries, and episcleritis. (from ama, drug evaluations annual, 1994, p2000) it had been used by mouth in rheumatic disorders such as ankylosing spondylitis, osteoarthritis, and rheumatoid arthritis but such use is no longer considered justified owing to the risk of severe hematological adverse effects. (from martindale, the extra pharmacopoeia, 30th ed, p27)Phenylbutazone
a butyl-diphenyl-pyrazolidinedione that has anti-inflammatory, antipyretic, and analgesic activities. it has been used in ankylosing spondylitis; rheumatoid arthritis; and reactive arthritis.
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 T39.2X1A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T39.2X1AOverview
Is T39.2X1A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by pyrazolone derivatives, accidental (unintentional), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T39.2X1A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by pyrazolone derivatives, accidental (unintentional), such as an emergency visit or first evaluation.
What MS-DRG does T39.2X1A group to?
When poisoning by pyrazolone derivatives, 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 T39.2X1A?
Under the General Equivalence Mappings, poisoning by pyrazolone derivatives, accidental (unintentional), initial encounter converts to ICD-9-CM 965.5 (poisoning-pyrazole deriv) and E850.5 (acc poison-pyrazole derv). 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.
