T46-T60
Medium Complexity
Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
Primary Specialty: Emergency Medicine
Last Updated: 2025-09-09
ICD-10 Codes (200)
0 billable188 category headers
T47T47.0T47.1T47.2T47.3T47.4T47.5T47.6T47.7T47.8T47.9T47.91T47.92T47.93T47.94T47.95T47.96T48T48.0T48.1T48.2T48.20T48.201T48.202T48.203T48.204T48.205T48.206T48.29T48.291T48.292T48.293T48.294T48.295T48.296T48.3T48.4T48.5T48.6T48.9T48.90T48.901T48.902T48.903T48.904T48.905T48.906T48.99T48.991T48.992T48.993T48.994T48.995T48.996T49T49.0T49.1T49.2T49.3T49.4T49.5T49.6T49.7T49.8T49.9T49.91T49.92T49.93T49.94T49.95T49.96T50T50.0T50.1T50.2T50.3T50.4T50.5T50.6T50.7T50.8T50.9T50.90T50.901T50.902T50.903T50.904T50.905T50.906T50.91T50.911T50.912T50.913T50.914T50.915T50.916T50.99T50.991T50.992T50.993T50.994T50.995T50.996T51T51.0T51.1T51.2T51.3T51.8T51.9T51.91T51.92T51.93T51.94T52T52.0T52.1T52.2T52.3T52.4T52.8T52.9T52.91T52.92T52.93T52.94T53T53.0T53.1T53.2T53.3T53.4T53.5T53.6T53.7T53.9T53.91T53.92T53.93T53.94T54T54.0T54.1T54.2T54.3T54.9T54.91T54.92T54.93T54.94T55T55.0T55.1T56T56.0T56.1T56.2T56.3T56.4T56.5T56.6T56.7T56.8T56.81T56.811T56.812T56.813T56.814T56.82T56.821T56.822T56.823T56.824T56.89T56.891T56.892T56.893T56.894T56.9T56.91T56.92T56.93T56.94T57T57.0T57.1T57.2T57.3T57.8T57.9T57.91T57.92T57.93T57.94T58T58.0T58.01T58.02T58.03T58.04Updates & Changes
FY 2026 Updates
Current Year
New Codes (2)
T40.411A
Poisoning by fentanyl, accidental (unintentional), initial encounter
T40.491A
Poisoning by other synthetic narcotics, accidental (unintentional), initial encounter
Revised Codes (1)
T40.2X1A
Poisoning by other opioids, accidental (unintentional) - updated to include synthetic opioid specifications
Deleted Codes
No codes deleted in this range for FY 2026
Historical Changes
- •FY 2025: Routine maintenance updates with minor terminology clarifications
- •FY 2024: Enhanced specificity requirements for certain code ranges
- •FY 2023: Updated documentation guidelines for improved clarity
Upcoming Changes
- •Proposed updates pending review by Coordination and Maintenance Committee
- •Under consideration: Enhanced digital health integration codes
Implementation Guidance
- •Review all FY 2026 updates for T46-T60 codes before implementation
- •Always verify the most current codes in the ICD-10-CM manual
- •Ensure clinical documentation supports the selected diagnosis codes
- +3 more guidance items...
Range Overview
high priority
The ICD-10 code range T46-T60 is dedicated to poisoning by, adverse effects of, and underdosing of drugs, medicaments, and biological substances. It covers a wide range of substances, from antibiotics to narcotics and psychodysleptics, and includes both accidental and intentional cases. These codes are used to document instances where a patient has been harmed or has experienced negative effects due to the use of a particular substance.
Key Usage Points:
- •Always specify the substance involved in the poisoning, adverse effect, or underdosing.
- •Include information on intent, such as accidental or intentional.
- •Use additional codes to identify any associated complications.
- •Specify the patient's status at the time of encounter.
- •Remember to code first for any associated withdrawal condition.
Coding Guidelines
When to Use:
- ✓When a patient presents with symptoms of poisoning due to a specific substance.
- ✓When a patient experiences adverse effects from a medication or biological substance.
- ✓In cases of underdosing, where the patient has taken less of a medication than prescribed.
- ✓When documenting a patient's history of substance-related issues.
- ✓In cases of substance abuse or dependency.
When NOT to Use:
- ✗When the patient's condition is not related to a substance.
- ✗When the substance involved is not specified.
- ✗When the patient's symptoms are due to a condition other than poisoning, adverse effects, or underdosing.
- ✗When the patient's condition is due to a non-medical substance.
- ✗When the patient's condition is due to an overdose of a substance not covered in this range.
Code Exclusions
Always verify exclusions with the patient's medical record and the ICD-10 guidelines.
Documentation Requirements
Documentation for these codes should include the specific substance involved, the intent (if applicable), and the patient's status at the time of encounter. Any associated complications should also be documented.
Clinical Information:
- •Specific substance involved
- •Intent (accidental, intentional, etc.)
- •Patient's status at time of encounter
- •Associated complications
- •History of substance-related issues
Supporting Evidence:
- •Medical history
- •Lab results
- •Physician's notes
- •Pharmacy records
Good Documentation Example:
Patient presented with symptoms of poisoning due to intentional ingestion of narcotic. Patient was conscious and cooperative at time of encounter. Lab results confirmed presence of narcotic in system.
Poor Documentation Example:
Patient presented with symptoms of poisoning.
Common Documentation Errors:
- âš Not specifying the substance involved
- âš Not documenting the intent
- âš Not including the patient's status at time of encounter
- âš Not coding for associated complications
Range Statistics
15
Total Codes
0
Billable
Complexity:
Medium
Primary Use:Clinical Documentation
Chapter:
Coding Complexity
Medium
Complexity Rating
The complexity of these codes comes from the need to accurately identify the specific substance involved, determine the intent, and document the patient's status at the time of encounter. Additionally, there are many codes within this range, which can make it difficult to find the most appropriate code.
Key Factors:
- â–¸Identifying the specific substance involved
- â–¸Determining the intent
- â–¸Documenting the patient's status at time of encounter
- â–¸Coding for associated complications
- â–¸Navigating the numerous codes within this range
Specialty Focus
These codes are frequently used in emergency medicine, toxicology, and psychiatry. They can also be relevant in any specialty where medications or biological substances are used.
Primary Specialties:
Emergency Medicine
40%
Toxicology
30%
Psychiatry
30%
Clinical Scenarios:
- • Patient presents with symptoms of poisoning due to accidental ingestion of a medication.
- • Patient experiences adverse effects from a newly prescribed medication.
- • Patient has taken less of a medication than prescribed, resulting in underdosing.
- • Patient with a history of substance abuse presents with symptoms of poisoning.
- • Patient presents with complications associated with poisoning, adverse effects, or underdosing.
Resources & References
There are numerous resources available for understanding and applying these codes, including the official ICD-10 guidelines, clinical reference sources, and educational materials.
Official Guidelines:
- ICD-10-CM Official Guidelines for Coding and Reporting
- National Center for Health Statistics (NCHS)
- World Health Organization (WHO)
Clinical References:
- American Academy of Clinical Toxicology (AACT)
- American Society of Addiction Medicine (ASAM)
Educational Materials:
- American Health Information Management Association (AHIMA)
- American Academy of Professional Coders (AAPC)
Frequently Asked Questions
How do I code for a patient who has taken less of a medication than prescribed?
This would be considered underdosing. You would use the appropriate code from the T46-T60 range, and include a code for the condition for which the medication was prescribed, if applicable.
What if the substance involved is not listed in the T46-T60 range?
If the substance is not listed in this range, you should use the code for the most similar substance that is listed. If no similar substance is listed, use the code for 'other' in the appropriate category.