ICD-10-CM diagnosis code
T42.0X4D Poisoning by hydantoin derivatives, undetermined, subsequent encounter
- Billable
- Yes, a complete code (FY2026)
Encounter (7th character)
This code is for a subsequent encounter: active treatment is complete and the patient is being seen during healing or recovery (for example a cast change, medication adjustment or follow-up visit).
Documenting T42.0X4D? Write the note in seconds
Paste your rough notes and get a structured SOAP note. Free, no account needed.
Other codes in T42
162 complete codes in this category.
- T42.0X2DPoisoning by hydantoin derivatives, intentional self-harm, subsequent encounter
- T42.0X2SPoisoning by hydantoin derivatives, intentional self-harm, sequela
- T42.0X3APoisoning by hydantoin derivatives, assault, initial encounter
- T42.0X3DPoisoning by hydantoin derivatives, assault, subsequent encounter
- T42.0X3SPoisoning by hydantoin derivatives, assault, sequela
- T42.0X4APoisoning by hydantoin derivatives, undetermined, initial encounter
- T42.0X4DPoisoning by hydantoin derivatives, undetermined, subsequent encounter
- T42.0X4SPoisoning by hydantoin derivatives, undetermined, sequela
- T42.0X5AAdverse effect of hydantoin derivatives, initial encounter
- T42.0X5DAdverse effect of hydantoin derivatives, subsequent encounter
- T42.0X5SAdverse effect of hydantoin derivatives, sequela
- T42.0X6AUnderdosing of hydantoin derivatives, initial encounter
Documentation tips
- Make sure the note supports every element of the title, “Poisoning by hydantoin derivatives, undetermined, subsequent encounter”: each detail in it should be traceable to the history, examination or assessment.
- Code to the highest specificity the documentation supports. If a detail is missing from the note, add it to the note rather than choosing a less specific code by default.
- Check the Tabular List and official guidelines for instructional notes (“code first”, “use additional code”, Excludes1/Excludes2) that apply to T42.
The international WHO ICD-10 also has T42, with its inclusion and exclusion notes; titles and detail can differ from ICD-10-CM.
ICD-10-CM is developed by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, and is based on the WHO ICD-10. Codes and titles are reproduced unchanged from the FY2026 code list (effective 1 October 2025). Their use here does not imply endorsement by CDC, HHS or the U.S. Government. Changes effective on or after 1 October 2026 may not be reflected yet; check the current release at cdc.gov or cms.gov before submitting claims.
Look up another code
Stop looking codes up by hand
Docdemic listens to the consultation, writes the note and suggests the diagnosis and procedure codes that fit it, each one checked against your country’s official code list.
Try Docdemic free