Summary & Overview
CPT 80339: Detection of One to Three Antiepileptic Medications
CPT code 80339 identifies laboratory testing for the presence or amount of one to three antiepileptic (anticonvulsant) medications in a patient specimen. This test is used when the specific antiepileptic agents being assessed are not captured by other, more specific CPT codes. Nationally, therapeutic drug monitoring and toxicology testing for antiepileptics support medication management, seizure control, and safety monitoring, making this code relevant to neurology, emergency medicine, and clinical laboratory operations.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context and typical service settings, payer coverage scope, common modifiers used with laboratory CPT codes, and benchmarking notes where available. The publication addresses how CPT code 80339 fits into laboratory service lines and the kinds of clinical scenarios that prompt use, such as therapeutic drug monitoring and undifferentiated seizure evaluation. Data not available in the input is explicitly noted where applicable.
This resource offers concise guidance on the code's clinical significance, expected sites of service, payer landscape, and the types of information clinicians and billing professionals should expect to find in payer policies and laboratory service catalogs.
Billing Code Overview
CPT code 80339 describes a laboratory test in which a lab analyst measures the amount of, or detects the presence of, one to three antiepileptic (anticonvulsant) medications in a patient specimen. The code is used when the specific antiepileptic(s) being tested are not specified by other CPT codes.
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Service type: Clinical laboratory drug level or qualitative/quantitative drug detection testing for antiepileptic medications
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Typical site of service: Hospital laboratory, independent clinical laboratory, or outpatient collection site where blood or other patient specimens are obtained and processed for therapeutic drug monitoring or toxicology screening
Clinical & Coding Specifications
Clinical Context
A 28-year-old patient with known epilepsy presents to an outpatient neurology clinic for routine therapeutic drug monitoring after seizure recurrence. The clinician orders serum antiepileptic drug levels to confirm adherence, assess subtherapeutic levels, and evaluate potential drug interactions. A phlebotomy draw is performed in the clinic or at an affiliated laboratory; the specimen is sent to the clinical laboratory where a laboratory analyst performs quantitative testing to measure the presence or amount of one to three antiepileptic medications not specified by other CPT codes. Typical workflow: clinician documents indication and orders the test → specimen collected at an outpatient clinic, hospital outpatient lab, or reference lab → specimen accessioned and analyzed by laboratory personnel using appropriate immunoassay or mass spectrometry methods → results reported to the ordering provider for dose adjustment or clinical decision-making. Typical site of service: outpatient clinic, hospital outpatient laboratory, or independent clinical laboratory. Typical patient scenario: routine monitoring of anticonvulsant therapy, evaluation after breakthrough seizures, suspected toxicity, or assessment when changing therapy or adding interacting medications.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When reporting only the reporting/interpretive portion separate from the technical component |