2026 ICD-10-CM Diagnosis Code T36.1X4SPoisoning by cephalosporins and other beta-lactam antibiotics, undetermined, sequela
T36.1X4S is a billable ICD-10-CM diagnosis code for poisoning by cephalosporins and other beta-lactam antibiotics, 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
T36.1X4S 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 systemic antibiotics (T36). 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
Aztreonam
a monocyclic beta-lactam antibiotic originally isolated from chromobacterium violaceum. it is resistant to beta-lactamases and is used in gram-negative infections, especially of the meninges, bladder, and kidneys. it may cause a superinfection with gram-positive organisms.Cefaclor
semisynthetic, broad-spectrum antibiotic derivative of cephalexin.Cefadroxil
long-acting, broad-spectrum, water-soluble, cephalexin derivative.Cefamandole
semisynthetic wide-spectrum cephalosporin with prolonged action, probably due to beta-lactamase resistance. it is used also as the nafate.Cefatrizine
orally active semisynthetic cephalosporin antibiotic with broad-spectrum activity.Cefazolin
a semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. it attains high serum levels and is excreted quickly via the urine.Cefixime
a third-generation cephalosporin antibiotic that is stable to hydrolysis by beta-lactamases.Cefmenoxime
a cephalosporin antibiotic that is administered intravenously or intramuscularly. it is active against most common gram-positive and gram-negative microorganisms, is a potent inhibitor of enterobacteriaceae, and is highly resistant to hydrolysis by beta-lactamases. the drug has a high rate of efficacy in many types of infection and to date no severe side effects have been noted.Cefmetazole
a semisynthetic cephamycin antibiotic with a broad spectrum of activity against both gram-positive and gram-negative microorganisms. it has a high rate of efficacy in many types of infection and to date no severe side effects have been noted.Cefonicid
a second-generation cephalosporin administered intravenously or intramuscularly. its bactericidal action results from inhibition of cell wall synthesis. it is used for urinary tract infections, lower respiratory tract infections, and soft tissue and bone infections.Cefoperazone
semisynthetic broad-spectrum cephalosporin with a tetrazolyl moiety that is resistant to beta-lactamase. it may be used to treat pseudomonas infections.Cefotaxime
semisynthetic broad-spectrum cephalosporin.Cefotetan
a semisynthetic cephamycin antibiotic that is administered intravenously or intramuscularly. the drug is highly resistant to a broad spectrum of beta-lactamases and is active against a wide range of both aerobic and anaerobic gram-positive and gram-negative microorganisms.Cefotiam
one of the cephalosporins that has a broad spectrum of activity against both gram-positive and gram-negative microorganisms.Cefoxitin
a semisynthetic cephamycin antibiotic resistant to beta-lactamase.Cefsulodin
a pyridinium-substituted semisynthetic, broad-spectrum antibacterial used especially for pseudomonas infections in debilitated patients.Ceftazidime
semisynthetic, broad-spectrum antibacterial derived from cephaloridine and used especially for pseudomonas and other gram-negative infections in debilitated patients.Ceftizoxime
a semisynthetic cephalosporin antibiotic which can be administered intravenously or by suppository. the drug is highly resistant to a broad spectrum of beta-lactamases and is active against a wide range of both aerobic and anaerobic gram-positive and gram-negative organisms. it has few side effects and is reported to be safe and effective in aged patients and in patients with hematologic disorders.Ceftriaxone
a broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears.Cefuroxime
broad-spectrum cephalosporin antibiotic resistant to beta-lactamase. it has been proposed for infections with gram-negative and gram-positive organisms, gonorrhea, and haemophilus.Cephalexin
a semisynthetic cephalosporin antibiotic with antimicrobial activity similar to that of cephaloridine or cephalothin, but somewhat less potent. it is effective against both gram-positive and gram-negative organisms.Cephalosporinase
a cephalosporin antibiotic.Cephaloglycin
a cephalorsporin antibiotic.Cephaloridine
a cephalosporin antibiotic.Cephalosporins
a group of broad-spectrum antibiotics first isolated from the mediterranean fungus acremonium. they contain the beta-lactam moiety thia-azabicyclo-octenecarboxylic acid also called 7-aminocephalosporanic acid.First Generation Cephalosporins
cephalosporin agents with excellent coverage against gram-positive cocci, such as staphylococcus and streptococcus. they have some activity against the gram-negative bacteria, but in general, gram-negative activity is decreased compared to 2nd, 3rd, and 4th generation cephalosporins.Second Generation Cephalosporins
agents with less activity against gram-positive cocci than first generation cephalosporins but have increased activity against gram-negative bacilli.Third Generation Cephalosporins
agents that are structurally similar to other cephalosporins but have a broader spectrum of activity against bacteria than the first and second generation cephalosporins. these agents cover more resistant streptococcus, staphylococcus, gram-positive anaerobes, and more resistant strains of haemophilus, neisseria, proteus, escherichia coli, and klebsiella (hnpek).Cephalothin
a cephalosporin antibiotic.Cephradine
a semi-synthetic cephalosporin antibiotic.Clavulanic Acid
a beta-lactam antibiotic produced by the actinobacterium streptomyces clavuligerus. it is a suicide inhibitor of bacterial beta-lactamase enzymes. administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.Clavulanic Acids
acids, salts, and derivatives of clavulanic acid (c8h9o5n). they consist of those beta-lactam compounds that differ from penicillin in having the sulfur of the thiazolidine ring replaced by an oxygen. they have limited antibacterial action, but block bacterial beta-lactamase irreversibly, so that similar antibiotics are not broken down by the bacterial enzymes and therefore can exert their antibacterial effects.
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
Antibiotics
Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply.
The full article covers:
- What are antibiotics?
- What do antibiotics treat?
- Do antibiotics treat viral infections?
- What are the side effects of antibiotics?
- Why is it important to take antibiotics only when they're needed?
- How do I use antibiotics correctly?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T36.1X4S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T36.1X4SOverview
Is T36.1X4S a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by cephalosporins and other beta-lactam antibiotics, undetermined, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T36.1X4S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by cephalosporins and other beta-lactam antibiotics, undetermined itself has resolved, not the original event.
What MS-DRG does T36.1X4S group to?
When poisoning by cephalosporins and other beta-lactam antibiotics, 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 T36.1X4S 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 cephalosporins and other beta-lactam antibiotics, undetermined, sequela on inpatient claims.
What is the ICD-9 equivalent of T36.1X4S?
Under the General Equivalence Mappings, poisoning by cephalosporins and other beta-lactam antibiotics, 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.
