T65.85 vs Z77
T65.85 (Toxic effect of medetomidine) compared with Z77 (Other contact with and (suspected) exposures hazardous to health), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. T65.85 carries an Excludes1 note covering Z77: “contact with and (suspected) exposure to toxic substances (Z77.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Yes, when both are documented. Z77 carries an Excludes2 note covering T65.85: “toxic effects of substances chiefly nonmedicinal as to source (T51-T65)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| T65.85Toxic effect of medetomidine | Z77Other contact with and (suspected) exposures hazardous to health | |
|---|---|---|
| Billing status | Non-billable header Report instead: T65.851A, T65.851D, T65.851S, T65.852A, T65.852D | Non-billable header |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | — | Other contact with and (suspected) exposures hazardous to health is a non-billable ICD-10-CM category code (Z77). |
| 7th character | The appropriate 7th character is to be added to each code from category T65 | — |
| Includes | — | contact with and (suspected) exposures to potential hazards to health |
| Use additional code | code to identify associated manifestations, such as: bradycardia NOS (R00.1) somnolence, stupor and coma (R40.-) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources