2026 ICD-10-CM Diagnosis Code T36.0X2APoisoning by penicillins, intentional self-harm, initial encounter
T36.0X2A is a billable ICD-10-CM diagnosis code for poisoning by penicillins, intentional self-harm, 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, self-harm; 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.
- Ampicillin overdose
- Carbenicillin overdose
- Cloxacillin overdose
- Flucloxacillin overdose
- Flucloxacillin poisoning
- Intentional ampicillin overdose
- Intentional ampicillin poisoning
- Intentional carbenicillin overdose
- Intentional carbenicillin poisoning
- Intentional cloxacillin overdose
- Intentional cloxacillin poisoning
- Intentional flucloxacillin overdose
- Intentional flucloxacillin poisoning
- Intentional penicillin G poisoning
- Intentional piperacillin poisoning
- Piperacillin poisoning
- Poisoning by ampicillin
- Poisoning by carbenicillin
- Poisoning by cloxacillin
- Poisoning by penicillin G
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
Amoxicillin
a broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration.Amoxicillin-Potassium Clavulanate Combination
a fixed-ratio combination of amoxicillin trihydrate and potassium clavulanate.Ampicillin
semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic.Ampicillin Resistance
nonsusceptibility of a microbe to the action of ampicillin, a penicillin derivative that interferes with cell wall synthesis.Pivampicillin
pivalate ester analog of ampicillin.Talampicillin
an ester of ampicillin which is readily hydrolyzed on absorption to release ampicillin. it is well absorbed from the gastrointestinal tract resulting in a greater bioavailability of ampicillin than can be achieved with equivalent doses of ampicillin.Azlocillin
a semisynthetic ampicillin-derived acylureido penicillin.Carbenicillin
broad-spectrum semisynthetic penicillin derivative used parenterally. it is susceptible to gastric juice and penicillinase and may damage platelet function.Carfecillin
the phenyl ester of carbenicillin that, upon oral administration, is broken down in the intestinal mucosa to the active antibacterial. it is used for urinary tract infections.Penicillinase
a beta-lactamase preferentially cleaving penicillins. (dorland, 28th ed) ec 3.5.2.-.Cloxacillin
a semi-synthetic antibiotic that is a chlorinated derivative of oxacillin.Cyclacillin
a cyclohexylamido analog of penicillanic acid.Dicloxacillin
one of the penicillins which is resistant to penicillinase.Cilastatin, Imipenem Drug Combination
combination of imipenem and cilastatin that is used in the treatment of bacterial infections; cilastatin inhibits renal dehydropeptidase i to prolong the half-life and increase the tissue penetration of imipenem, enhancing its efficacy as an anti-bacterial agent.Imipenem
semisynthetic thienamycin that has a wide spectrum of antibacterial activity against gram-negative and gram-positive aerobic and anaerobic bacteria, including many multiresistant strains. it is stable to beta-lactamases. clinical studies have demonstrated high efficacy in the treatment of infections of various body systems. its effectiveness is enhanced when it is administered in combination with cilastatin, a renal dipeptidase inhibitor.Methicillin
one of the penicillins which is resistant to penicillinase but susceptible to a penicillin-binding protein. it is inactivated by gastric acid so administered by injection.Methicillin Resistance
non-susceptibility of a microbe to the action of methicillin, a semi-synthetic penicillin derivative.Methicillin-Resistant Staphylococcus aureus
a strain of staphylococcus aureus that is non-susceptible to the action of methicillin. the mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins.Mezlocillin
semisynthetic ampicillin-derived acylureido penicillin. it has been proposed for infections with certain anaerobes and may be useful in inner ear, bile, and cns infections.Nafcillin
a semi-synthetic antibiotic related to penicillin.Oxacillin
an antibiotic similar to flucloxacillin used in resistant staphylococci infections.Piperacillin
semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. it is also used in combination with other antibiotics.Piperacillin, Tazobactam Drug Combination
an antibiotic combination product of piperacillin and tazobactam, a penicillanic acid derivative with enhanced beta-lactamase inhibitory activity, that is used for the intravenous treatment of intra-abdominal, pelvic, and skin infections and for community-acquired pneumonia of moderate severity. it is also used for the treatment of pseudomonas aeruginosa infections.Sulbactam
a beta-lactamase inhibitor with very weak antibacterial action. the compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone.Sulbenicillin
semisynthetic penicillin-type antibiotic.Ticarcillin
an antibiotic derived from penicillin similar to carbenicillin in action.
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 T36.0X2A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T36.0X2AOverview
Is T36.0X2A (Poisoning by penicillins, intentional self-harm) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by penicillins, intentional self-harm, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T36.0X2A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by penicillins, intentional self-harm, such as an emergency visit or first evaluation.
What MS-DRG does T36.0X2A group to?
When poisoning by penicillins, intentional self-harm, 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 T36.0X2A?
Under the General Equivalence Mappings, poisoning by penicillins, intentional self-harm, initial encounter converts to ICD-9-CM 960.0 (poisoning-penicillins) and E950.4 (poison-drug/medicin NEC). 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.
