2024 ICD-10-CM Diagnosis Code T50.9

Poisoning by, adverse effect of and underdosing of other and unspecified drugs, medicaments and biological substances

ICD-10-CM Code:
T50.9
ICD-10 Code for:
And unsp drugs, medicaments and biological substances
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
      (T36-T50)
      • Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances
        (T50)

T50.9 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of poisoning by, adverse effect of and underdosing of other and unspecified drugs, medicaments and biological substances. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like T50.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to And unsp drugs, medicaments and biological substances

Non-specific codes like T50.9 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for and unsp drugs, medicaments and biological substances:

  • T50.90 for Poisoning by, adverse effect of and underdosing of unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • T50.901 for Poisoning by unspecified drugs, medicaments and biological substances, accidental (unintentional) - NON-BILLABLE CODE

  • Use T50.901A for initial encounter - BILLABLE CODE

  • Use T50.901D for subsequent encounter - BILLABLE CODE

  • Use T50.901S for sequela - BILLABLE CODE

  • T50.902 for Poisoning by unspecified drugs, medicaments and biological substances, intentional self-harm - NON-BILLABLE CODE

  • Use T50.902A for initial encounter - BILLABLE CODE

  • Use T50.902D for subsequent encounter - BILLABLE CODE

  • Use T50.902S for sequela - BILLABLE CODE

  • T50.903 for Poisoning by unspecified drugs, medicaments and biological substances, assault - NON-BILLABLE CODE

  • Use T50.903A for initial encounter - BILLABLE CODE

  • Use T50.903D for subsequent encounter - BILLABLE CODE

  • Use T50.903S for sequela - BILLABLE CODE

  • T50.904 for Poisoning by unspecified drugs, medicaments and biological substances, undetermined - NON-BILLABLE CODE

  • Use T50.904A for initial encounter - BILLABLE CODE

  • Use T50.904D for subsequent encounter - BILLABLE CODE

  • Use T50.904S for sequela - BILLABLE CODE

  • T50.905 for Adverse effect of unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.905A for initial encounter - BILLABLE CODE

  • Use T50.905D for subsequent encounter - BILLABLE CODE

  • Use T50.905S for sequela - BILLABLE CODE

  • T50.906 for Underdosing of unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.906A for initial encounter - BILLABLE CODE

  • Use T50.906D for subsequent encounter - BILLABLE CODE

  • Use T50.906S for sequela - BILLABLE CODE

  • T50.91 for Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • T50.911 for Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional) - NON-BILLABLE CODE

  • Use T50.911A for initial encounter - BILLABLE CODE

  • Use T50.911D for subsequent encounter - BILLABLE CODE

  • Use T50.911S for sequela - BILLABLE CODE

  • T50.912 for Poisoning by multiple unspecified drugs, medicaments and biological substances, intentional self-harm - NON-BILLABLE CODE

  • Use T50.912A for initial encounter - BILLABLE CODE

  • Use T50.912D for subsequent encounter - BILLABLE CODE

  • Use T50.912S for sequela - BILLABLE CODE

  • T50.913 for Poisoning by multiple unspecified drugs, medicaments and biological substances, assault - NON-BILLABLE CODE

  • Use T50.913A for initial encounter - BILLABLE CODE

  • Use T50.913D for subsequent encounter - BILLABLE CODE

  • Use T50.913S for sequela - BILLABLE CODE

  • T50.914 for Poisoning by multiple unspecified drugs, medicaments and biological substances, undetermined - NON-BILLABLE CODE

  • Use T50.914A for initial encounter - BILLABLE CODE

  • Use T50.914D for subsequent encounter - BILLABLE CODE

  • Use T50.914S for sequela - BILLABLE CODE

  • T50.915 for Adverse effect of multiple unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.915A for initial encounter - BILLABLE CODE

  • Use T50.915D for subsequent encounter - BILLABLE CODE

  • Use T50.915S for sequela - BILLABLE CODE

  • T50.916 for Underdosing of multiple unspecified drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.916A for initial encounter - BILLABLE CODE

  • Use T50.916D for subsequent encounter - BILLABLE CODE

  • Use T50.916S for sequela - BILLABLE CODE

  • T50.99 for Poisoning by, adverse effect of and underdosing of other drugs, medicaments and biological substances - NON-BILLABLE CODE

  • T50.991 for Poisoning by other drugs, medicaments and biological substances, accidental (unintentional) - NON-BILLABLE CODE

  • Use T50.991A for initial encounter - BILLABLE CODE

  • Use T50.991D for subsequent encounter - BILLABLE CODE

  • Use T50.991S for sequela - BILLABLE CODE

  • T50.992 for Poisoning by other drugs, medicaments and biological substances, intentional self-harm - NON-BILLABLE CODE

  • Use T50.992A for initial encounter - BILLABLE CODE

  • Use T50.992D for subsequent encounter - BILLABLE CODE

  • Use T50.992S for sequela - BILLABLE CODE

  • T50.993 for Poisoning by other drugs, medicaments and biological substances, assault - NON-BILLABLE CODE

  • Use T50.993A for initial encounter - BILLABLE CODE

  • Use T50.993D for subsequent encounter - BILLABLE CODE

  • Use T50.993S for sequela - BILLABLE CODE

  • T50.994 for Poisoning by other drugs, medicaments and biological substances, undetermined - NON-BILLABLE CODE

  • Use T50.994A for initial encounter - BILLABLE CODE

  • Use T50.994D for subsequent encounter - BILLABLE CODE

  • Use T50.994S for sequela - BILLABLE CODE

  • T50.995 for Adverse effect of other drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.995A for initial encounter - BILLABLE CODE

  • Use T50.995D for subsequent encounter - BILLABLE CODE

  • Use T50.995S for sequela - BILLABLE CODE

  • T50.996 for Underdosing of other drugs, medicaments and biological substances - NON-BILLABLE CODE

  • Use T50.996A for initial encounter - BILLABLE CODE

  • Use T50.996D for subsequent encounter - BILLABLE CODE

  • Use T50.996S for sequela - BILLABLE CODE

Coding Guidelines

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 aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Patient Education


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.

What is a drug interaction?

A drug interaction is a change in the way a drug acts in the body when taken with certain other drugs, foods, or supplements or when taken while you have certain medical conditions. Examples include:

  • Two drugs, such as aspirin and blood thinners
  • Drugs and food, such as statins and grapefruit
  • Drugs and supplements, such as gingko and blood thinners
  • Drugs and medical conditions, such as aspirin and peptic ulcers

Interactions could cause a drug to be more or less effective, cause side effects, or change the way one or both drugs work.

What are side effects?

Side effects are unwanted, usually unpleasant, effects caused by medicines. Most are mild, such as a stomachache, dry mouth, or drowsiness, and go away after you stop taking the medicine. Others can be more serious. Sometimes a drug can interact with a disease that you have and cause a side effect. For example, if you have a heart condition, certain decongestants can cause you to have a rapid heartbeat.

What are drug allergies?

Drug allergies are another type of reaction. They can range from mild to life-threatening. Skin reactions, such as hives and rashes, are the most common type. Anaphylaxis, a serious allergic reaction, is less common.

How can I stay safe when taking medicines?

When you start a new prescription or over-the-counter medicine, make sure you understand how to take it correctly. Know which other medicines, foods, and supplements you need to avoid. Always talk to your health care provider or pharmacist if you have questions about your medicines.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.