T42.5X1A — Poisoning by mixed antiepileptics, accidental (unintentional), initial encounter
Is T42.5X1A billable?
Yes — T42.5X1A is billable for FY2027. T42.5X1A is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T42.5X1A may be submitted for encounters from October 1, 2026 through September 30, 2027.
T42.5X1A at a glance
| Code | T42.5X1A |
|---|---|
| Description | Poisoning by mixed antiepileptics, accidental (unintentional), initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in T42.5X1A?
In T42.5X1A, the 7th character A means initial encounter. The 7th character is required for T42.5X1A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T42.5X1A group to?
T42.5X1A sits in MDC 21 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 917Poisoning and Toxic Effects of Drugs with MCCmedical
- 918Poisoning and Toxic Effects of Drugs without MCCmedical
Inclusion terms
Alternative wording in documentation that is classified to T42.5X1A.
- Poisoning by mixed antiepileptics NOS
Excludes1 — never code together — inherited from T36-T50
The conditions below can never be reported together with T42.5X1A 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 T42.5X1A. T42.5X1A describes a manifestation and cannot be the principal or first-listed diagnosis.
Use additional code — inherited from Chapter 19
Report an additional code alongside T42.5X1A to fully describe the condition. T42.5X1A 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 T42.5X1A to fully describe the condition. T42.5X1A is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T42.5X1A, but a patient may have both at the same time. When documentation supports it, T42.5X1A and the excluded code may both be reported.
Excludes2 — not included here — inherited from T36-T50
The conditions below are not part of T42.5X1A, but a patient may have both at the same time. When documentation supports it, T42.5X1A and the excluded code may both be reported.
Excludes2 — not included here — inherited from T42
The conditions below are not part of T42.5X1A, but a patient may have both at the same time. When documentation supports it, T42.5X1A and the excluded code may both be reported.
- drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.--F19.-)
How long has T42.5X1A existed?
T42.5X1A 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.