T57.3X2 (Toxic effect of hydrogen cyanide, intentional self-harm) compared with T57.3X4 (Toxic effect of hydrogen cyanide, undetermined), from the official CMS tabular data. T57.3X2 and T57.3X4 code the same substance (HCN) with a different intent. MedCoder-derived
Same substance, different circumstance of exposure.
Same substance — undetermined intent (HCN)
Accidental poisoning, intentional self-harm, assault, undetermined intent, adverse effect and underdosing are mutually exclusive columns — exactly one applies to a given encounter.
Source: CMS Table of Drugs and Chemicals
Same substance, different intent. T57.3X2 and T57.3X4 code the same substance (HCN) with a different circumstance of exposure.
From the CMS/CDC Table of Drugs and Chemicals: accidental poisoning, intentional self-harm, assault, undetermined intent, adverse effect and underdosing are mutually exclusive columns — only one of them applies to a given encounter.
| T57.3X2Toxic effect of hydrogen cyanide, intentional self-harm | T57.3X4Toxic effect of hydrogen cyanide, undetermined | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Toxic effect of hydrogen cyanide, intentional self-harm is a non-billable ICD-10-CM category code (T57.3X2). | Toxic effect of hydrogen cyanide, undetermined is a non-billable ICD-10-CM category code (T57.3X4). |
| 7th character | The appropriate 7th character is to be added to each code from category T57 | The appropriate 7th character is to be added to each code from category T57 |
| Use additional code | code(s): for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70) personal history of foreign body fully removed (Z87.821) | code(s): for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70) personal history of foreign body fully removed (Z87.821) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources