T65 Toxic effect of other and unspecified substances

The ICD-10-CM code for Toxic effect of other and unspecified substances is T65 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

19: Injury, poisoning and certain other consequences of external causes (S00-T88)

Section

T51-T65: Toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Category T65

84 codes (60 billable)

FY2026 Status

Stable since FY2024

Official Coding Guidelines

T36-T65 are combination codes; no additional external cause code

e. Adverse Effects, Poisoning, Underdosing and Toxic Effects Codes in categories T36-T65 are combination codes that include the substance that was taken as well as the intent. No additional external cause code is required for poisonings, toxic effects, adverse effects and underdosing codes.

Toxic effects: code T51-T65 first, then manifestations

(d) Toxic Effects When a harmful substance is ingested or comes in contact with a person, this is classified as a toxic effect. The toxic effect codes are in categories T51-T65. When coding a toxic effect, assign the toxic effect code first, followed by codes for all associated manifestations of the toxic effect.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool