2026 ICD-10-CM Diagnosis Code T50.5X4APoisoning by appetite depressants, undetermined, initial encounter
T50.5X4A is a billable ICD-10-CM diagnosis code for poisoning by appetite depressants, undetermined, 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, undetermined; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.
Code Identity
Code Classification
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 diuretics and other and unspecified drugs, medicaments and biological substances (T50). 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
Aminorex
an amphetamine-like anorectic agent. it may cause pulmonary hypertension.Benzphetamine
a sympathomimetic agent with properties similar to dextroamphetamine. it is used in the treatment of obesity. (from martindale, the extra pharmacopoeia, 30th ed, p1222)Chlorphentermine
a sympathomimetic agent that was formerly used as an anorectic. it has properties similar to those of dextroamphetamine. it has been implicated in lipid storage disorders and pulmonary hypertension. (from martindale, the extra pharmacopoeia, 30th ed, p1223)Dexfenfluramine
the s-isomer of fenfluramine. it is a serotonin agonist and is used as an anorectic. unlike fenfluramine, it does not possess any catecholamine agonist activity.Diethylpropion
a appetite depressant considered to produce less central nervous system disturbance than most drugs in this therapeutic category. it is also considered to be among the safest for patients with hypertension. (from ama drug evaluations annual, 1994, p2290)Fenfluramine
a centrally active drug that apparently both blocks serotonin uptake and provokes transport-mediated serotonin release.Mazindol
tricyclic anorexigenic agent unrelated to and less toxic than amphetamine, but with some similar side effects. it inhibits uptake of catecholamines and blocks the binding of cocaine to the dopamine uptake transporter.Phenmetrazine
a sympathomimetic drug used primarily as an appetite depressant. its actions and mechanisms are similar to dextroamphetamine.Phentermine
a central nervous system stimulant and sympathomimetic with actions and uses similar to those of dextroamphetamine. it has been used most frequently in the treatment of obesity.
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 T50.5X4A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T50.5X4AOverview
Is T50.5X4A (Poisoning by appetite depressants, undetermined) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by appetite depressants, undetermined, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T50.5X4A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by appetite depressants, undetermined, such as an emergency visit or first evaluation.
What MS-DRG does T50.5X4A group to?
When poisoning by appetite depressants, undetermined, 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 T50.5X4A?
Under the General Equivalence Mappings, poisoning by appetite depressants, undetermined, initial encounter converts to ICD-9-CM 977.0 (poisoning-dietetics) and E980.4 (undet pois-med agnt 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.
