CPT 80340 Antiepileptic Drug Assay Reimbursement

CPT code 80340 identifies a laboratory assay that detects or quantifies four to six antiepileptic (anticonvulsant) medications in a patient specimen. This test supports clinical management of patients with epilepsy or seizure disorders by confirming therapeutic levels, detecting nonadherence, identifying drug interactions, and guiding dose adjustments. Nationally, standardized reporting of such multi-drug assays affects laboratory services utilization and payer coverage policies for therapeutic drug monitoring.

Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical role of the assay, typical sites of service, and the common modifiers used in billing. The publication summarizes benchmark considerations for laboratory billing of multi-drug antiepileptic assays, highlights policy and coverage factors affecting reimbursement, and outlines clinical context for ordering such tests.

The content serves clinicians, laboratory managers, and billing specialists seeking a national-level reference for CPT code 80340, including service characterization, payer landscape, and practical billing context. Data not available in the input is noted where applicable.

Billing Code Overview

CPT code 80340 describes a laboratory test in which a lab analyst measures the amount of, or detects the presence of, four to six antiepileptic (anticonvulsant/antiseizure) medications in a patient specimen. Service type: Therapeutic drug monitoring / quantitative drug assay for multiple antiepileptic agents. Typical site of service: Clinical laboratory or hospital laboratory processing patient specimens collected in outpatient or inpatient settings.

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Clinical Context

A 28-year-old patient with known focal epilepsy on multiple antiseizure medications presents for routine therapeutic drug monitoring after a seizure recurrence. The clinician orders comprehensive antiepileptic drug level testing because the patient is taking several anticonvulsants and the exact agents or combinations are not covered by single-drug assays. A blood specimen is collected in the ambulatory lab or hospital phlebotomy unit and sent to the clinical chemistry/toxicology laboratory. The lab analyst performs a quantitative or qualitative assay that measures or detects the presence of four to six antiepileptic agents in the specimen, generating results used by the neurologist or primary care provider to adjust dosing, assess adherence, or investigate toxicity. Typical site of service includes hospital outpatient laboratory, independent clinical laboratory, or inpatient hospital laboratory; ordering providers commonly include neurologists, psychiatrists, or emergency medicine clinicians.

Coding Specifications

Modifier	Description	When to Use
`00`	Default/No modifier	Used when no other modifier applies to the claim.
`22`	Increased procedural services	When the laboratory documents substantially greater effort or complexity for testing (rare for standardized assays).

Taxonomy Code	Specialty	Notes
207RH0000X	Neurology	Neurologists commonly order antiepileptic drug monitoring and interpret results.
2084P0800X	Clinical Pathology/Laboratory	Clinical chemists and laboratory medicine specialists perform and oversee assays.
208000000X	Emergency Medicine	Emergency clinicians may order broad antiepileptic panels in acute presentations.
2084N0400X	Clinical Neurophysiology	Specialists involved in epilepsy care who may order drug level testing.
207VP0000X	Psychiatry	Psychiatrists manage antiseizure medications used for mood or seizure disorders and may order monitoring.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G40.909`	Epilepsy, unspecified, not intractable, without status epilepticus	Common primary diagnosis indicating epilepsy where antiepileptic drug monitoring is clinically indicated.
`G40.3`	Generalized idiopathic epilepsy and epileptic syndromes	Relevant for ongoing therapeutic drug monitoring in generalized epilepsy management.
`G40.8`	Other epilepsy and recurrent seizures	Used for varied seizure disorders where multimedication monitoring may be necessary.
`G41.9`	Status epilepticus, unspecified	Acute severe seizure activity prompting broad antiepileptic drug level assessment.
`R56.9`	Unspecified convulsions	Presentations with convulsions often trigger comprehensive antiepileptic and toxicology testing.
`Z79.899`	Other long term (current) drug therapy	Documentation of chronic antiepileptic use supporting periodic drug level monitoring.
`F44.5`	Conversion disorder with seizures or convulsions	Differential diagnosis where laboratory confirmation of antiseizure medication levels can aid management.
`T42.4X5A`	Poisoning by benzodiazepines, initial encounter	Toxicology or polypharmacy concerns may necessitate multi-antiseizure or multi-drug panels.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80104`	Drug screen, qualitative; multiple drug classes by presumptive test, capable of being read by direct optical observation	Often performed as an initial rapid screen for multiple agents prior to specific antiepileptic quantification.
`80331`	Drug analysis, qualitative; illicit drugs, simultaneous assay of multiple drugs, instrumented method	May be used in parallel when concern for nonprescribed substances or polypharmacy exists.
`80341`	Antiepileptic drug assay, complex, quantitative, four to six drugs (specific analytes specified in code)	Closely related; used when the panel targets specific named antiepileptics covered by other CPT coding — `80340` is for unspecified antiepileptics.
`84133`	Assay of drug, multiple anticonvulsants, quantitative, each	Individual anticonvulsant quantitative assays may be ordered alongside a panel for specific therapeutic ranges.
`36415`	Collection of venous blood by venipuncture	Commonly performed prior to running `80340` to obtain the patient specimen.
`82542`	Therapeutic drug assay, other; multiple drugs (example code for drug monitoring panels)	Represents additional therapeutic drug monitoring panels that may be billed in conjunction with antiepileptic testing.

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Summary & Overview

CPT 80340: Multiple Antiepileptic Drug Assay (4–6 Agents)