ICD-10-CM Diagnosis Code T65.91 - Toxic effect of unspecified substance, accidental (unintentional) (original) (raw)

ICD List 2025-2026 Edition

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2. ICD-10-CM Codes
3. S00–T88
4. T51-T65
5. T65
6. 2026 ICD-10-CM Code T65.91

Toxic effect of unspecified substance, accidental (unintentional)

ICD-10-CM Code:

T65.91

ICD-10 Code for:

Toxic effect of unsp substance, accidental (unintentional)

Is Billable?

Not Valid for Submission

Code Navigator:

T65.91 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity from the list below for a diagnosis of toxic effect of unspecified substance, accidental (unintentional). The code is not specific and is NOT valid for the year 2026 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 T65.91 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.

Non-specific codes like T65.91 require more digits to indicate the appropriate level of specificity. Consider using any of the following billable codes with a higher level of specificity when coding for toxic effect of unsp substance, accidental (unintentional):

Use T65.91XA for initial encounter

Use T65.91XD for subsequent encounter

Use T65.91XS for sequela

1. Code Information
2. Specific Coding
3. Coding Guidelines
4. Tabular List of Diseases and Injuries
5. Index to Diseases and Injuries References
7. Table of Drugs and Chemicals
8. Patient Education
9. Other Codes Used Similar Conditions
10. Code History

• Injury, poisoning and certain other consequences of external causes
  S00–T88
  • Toxic effects of substances chiefly nonmedicinal as to source
    T51-T65
    * Toxic effect of other and unspecified substances
    T65

The appropriate 7th character is to be added to each code from block Toxic effect of other and unspecified substances (T65). Use the following options for the aplicable episode of care:

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

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

• - Toxic (poisoning) - See Also: condition; - T65.91

References found for this diagnosis code in the External Cause of Injuries Index:

• Toxic(poisoning)

The code is referenced in the Table of Drugs and Chemicals, this table contains a classification of drugs, industrial solvents, corrosive gases, noxious plants, pesticides, and other toxic agents.

According to ICD-10-CM coding guidelines it is advised to do not code directly from the Table of Drugs and Chemicals, instead always refer back to the Tabular List when doing the initial coding. Each substance in the table is assigned a code according to the poisoning classification and external causes of adverse effects. It is important to use as many codes as necessary to specify all reported drugs, medicinal or chemical substances. If the same diagnosis code describes the causative agent for more than one adverse reaction, poisoning, toxic effect or underdosing, utilize the code only once.

Filter table of drugs and chemicals:

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:

• Prescription or over-the-counter medicines taken in doses that are too high
• Overdoses of illegal drugs
• Carbon monoxide from gas appliances
• Household products, such as laundry powder or furniture polish
• Pesticides
• Indoor or outdoor plants
• Metals such as lead and mercury

The effects of poisoning range from short-term illness to brain damage, coma, and death. To prevent poisoning it is important to use and store products exactly as their labels say. Keep dangerous products where children can't get to them. Treatment for poisoning depends on the type of poison. If you suspect someone has been poisoned, call your local poison control center at 1-800-222-1222 right away.

[Learn More in MedlinePlus]

• FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026

• FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025

• 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.

• Previous Code: T65.9

• Parent Code: T65.9

• Next Code: T65.91XA