2026 ICD-10-CM Diagnosis Code T37.0X4SPoisoning by sulfonamides, undetermined, sequela
T37.0X4S is a billable ICD-10-CM diagnosis code for poisoning by sulfonamides, undetermined, 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
Code Classification
Present on Admission (POA)Billing
T37.0X4S 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 other systemic anti-infectives and antiparasitics (T37). 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
Acedapsone
acetylated sulfone that is slowly metabolized to give long-term, low blood levels of dapsone. it has antimicrobial and antimalarial action, but is mainly used as a depot leprostatic agent.Sulfachlorpyridazine
a sulfonamide antimicrobial used for urinary tract infections and in veterinary medicine.Silver Sulfadiazine
antibacterial used topically in burn therapy.Sulfadiazine
one of the short-acting sulfonamides used in combination with pyrimethamine to treat toxoplasmosis in patients with acquired immunodeficiency syndrome and in newborns with congenital infections.Sulfadimethoxine
a sulfanilamide that is used as an anti-infective agent.Sulfadoxine
a long acting sulfonamide that is used, usually in combination with other drugs, for respiratory, urinary tract, and malarial infections.Sulfaguanidine
a sulfanilamide antimicrobial agent that is used to treat enteric infections.Sulfalene
long-acting plasma-bound sulfonamide used for respiratory and urinary tract infections and also for malaria.Sulfamerazine
a sulfanilamide that is used as an antibacterial agent.Sulfameter
long acting sulfonamide used in leprosy, urinary, and respiratory tract infections.Sulfamethazine
a sulfanilamide anti-infective agent. it has a spectrum of antimicrobial action similar to other sulfonamides.Sulfamethizole
a sulfathiazole antibacterial agent.Sulfamethoxazole
a bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. its broad spectrum of activity has been limited by the development of resistance. (from martindale, the extra pharmacopoeia, 30th ed, p208)Trimethoprim, Sulfamethoxazole Drug Combination
a drug combination with broad-spectrum antibacterial activity against both gram-positive and gram-negative organisms. it is effective in the treatment of many infections, including pneumocystis pneumonia in aids.Sulfamethoxypyridazine
a sulfanilamide antibacterial agent.Sulfamonomethoxine
long acting sulfonamide antibacterial agent.Sulfamoxole
a sulfanilamide antibacterial agent.Sulfanilamide
a short-acting sulfonamide used as an anti-infective agent. it has lower anti-bacterial activity than sulfamethoxazole.Sulfanilamides
compounds based on 4-aminobenzenesulfonamide. the '-anil-' part of the name refers to aniline.Sulfaphenazole
a sulfonilamide anti-infective agent.Sulfapyridine
antibacterial, potentially toxic, used to treat certain skin diseases.Sulfasalazine
a drug that is used in the management of inflammatory bowel diseases. its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid (see mesalamine) released in the colon. (from martindale, the extra pharmacopoeia, 30th ed, p907)Sulfathiazole
a sulfathiazole compound that is used as a short-acting anti-infective agent. it is no longer commonly used systemically due to its toxicity, but may still be applied topically in combination with other drugs for the treatment of vaginal and skin infections, and is still used in veterinary medicine.Sulfathiazoles
sulfanilamides consisting of a 4-aminobenzenesulfonamido group at the 2-position of 1,3-thiazole. they are often used as anti-infective agents.Sulfisomidine
a sulfanilamide antibacterial agent.Sulfisoxazole
a short-acting sulfonamide antibacterial with activity against a wide range of gram- negative and gram-positive organisms.
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
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 T37.0X4S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T37.0X4SOverview
Is T37.0X4S (Poisoning by sulfonamides, undetermined) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by sulfonamides, undetermined, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T37.0X4S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by sulfonamides, undetermined itself has resolved, not the original event.
What MS-DRG does T37.0X4S group to?
When poisoning by sulfonamides, undetermined, 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 T37.0X4S 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 sulfonamides, undetermined, sequela on inpatient claims.
What is the ICD-9 equivalent of T37.0X4S?
Under the General Equivalence Mappings, poisoning by sulfonamides, undetermined, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E989 (late eff inj-undet circ). 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.
