T42.5 — Poisoning by, adverse effect of and underdosing of mixed antiepileptics
Is T42.5 billable?
No — T42.5 is a non-billable header code. T42.5 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 18 billable codes beneath T42.5.
Billable codes under this header
- T42.5X1APoisoning by mixed antiepileptics, accidental (unintentional), initial encounter
- T42.5X1DPoisoning by mixed antiepileptics, accidental (unintentional), subsequent encounter
- T42.5X1SPoisoning by mixed antiepileptics, accidental (unintentional), sequela
- T42.5X2APoisoning by mixed antiepileptics, intentional self-harm, initial encounter
- T42.5X2DPoisoning by mixed antiepileptics, intentional self-harm, subsequent encounter
- T42.5X2SPoisoning by mixed antiepileptics, intentional self-harm, sequela
- T42.5X3APoisoning by mixed antiepileptics, assault, initial encounter
- T42.5X3DPoisoning by mixed antiepileptics, assault, subsequent encounter
- T42.5X3SPoisoning by mixed antiepileptics, assault, sequela
- T42.5X4APoisoning by mixed antiepileptics, undetermined, initial encounter
- T42.5X4DPoisoning by mixed antiepileptics, undetermined, subsequent encounter
- T42.5X4SPoisoning by mixed antiepileptics, undetermined, sequela
- T42.5X5AAdverse effect of mixed antiepileptics, initial encounter
- T42.5X5DAdverse effect of mixed antiepileptics, subsequent encounter
- T42.5X5SAdverse effect of mixed antiepileptics, sequela
- T42.5X6AUnderdosing of mixed antiepileptics, initial encounter
- T42.5X6DUnderdosing of mixed antiepileptics, subsequent encounter
- T42.5X6SUnderdosing of mixed antiepileptics, sequela
T42.5 at a glance
| Code | T42.5 |
|---|---|
| Description | Poisoning by, adverse effect of and underdosing of mixed antiepileptics |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together — inherited from T36-T50
The conditions below can never be reported together with T42.5 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- toxic reaction to local anesthesia in pregnancy (O29.3-)
Code first — inherited from T36-T50
The underlying condition below must be sequenced before T42.5. T42.5 describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T42.5 to fully describe the condition. T42.5 is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T36-T50
Report an additional code alongside T42.5 to fully describe the condition. T42.5 is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T42.5, but a patient may have both at the same time. When documentation supports it, T42.5 and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T42.5, but a patient may have both at the same time. When documentation supports it, T42.5 and the excluded code may both be reported.
Excludes2 — not included here — inherited from T42
The conditions below are not part of T42.5, but a patient may have both at the same time. When documentation supports it, T42.5 and the excluded code may both be reported.
- drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.--F19.-)
What codes fall under T42.5? (1)
How long has T42.5 existed?
T42.5 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
What other codes are in the T42 family? (8)
- T42.0Poisoning by, adverse effect of and underdosing of hydantoin derivativesnot billable
- T42.1Poisoning by, adverse effect of and underdosing of iminostilbenesnot billable
- T42.2Poisoning by, adverse effect of and underdosing of succinimides and oxazolidinedionesnot billable
- T42.3Poisoning by, adverse effect of and underdosing of barbituratesnot billable
- T42.4Poisoning by, adverse effect of and underdosing of benzodiazepinesnot billable
- T42.6Poisoning by, adverse effect of and underdosing of other antiepileptic and sedative-hypnotic drugsnot billable
- T42.7Poisoning by, adverse effect of and underdosing of unspecified antiepileptic and sedative-hypnotic drugsnot billable
- T42.8Poisoning by, adverse effect of and underdosing of antiparkinsonism drugs and other central muscle-tone depressantsnot billable