2026 ICD-10-CM Diagnosis Code T39.2X5SAdverse effect of pyrazolone derivatives, sequela
T39.2X5S is a billable ICD-10-CM diagnosis code for adverse effect of pyrazolone derivatives, 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 not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T39.2X5S.
Present on Admission (POA)Billing
T39.2X5S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adverse reaction to aldehyde
- Adverse reaction to aminophenazone
- Adverse reaction to chloral and/or chloral derivative
- Adverse reaction to pyrazole derivative
- Azapropazone adverse reaction
- Dichloralphenazone adverse reaction
- Dipyrone adverse reaction
- Hypothyroidism caused by drug
- Hypothyroidism resulting from phenylbutazone
- Oxyphenbutazone adverse reaction
- Phenylbutazone adverse reaction
- Uricosuric agent 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 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
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 T39.2X5S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T39.2X5SOverview
Is T39.2X5S (Adverse effect of pyrazolone derivatives) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of pyrazolone derivatives, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T39.2X5S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of pyrazolone derivatives itself has resolved, not the original event.
What MS-DRG does T39.2X5S group to?
On inpatient claims, adverse effect of pyrazolone derivatives, sequela maps to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T39.2X5S be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of pyrazolone derivatives, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
Is T39.2X5S 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 adverse effect of pyrazolone derivatives, sequela on inpatient claims.
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.
