Summary & Overview
CPT 80164: Total Valproic Acid (Dipropylacetic Acid) Blood Level
CPT code 80164 denotes a laboratory assay for total valproic acid (dipropylacetic acid) in blood, a key therapeutic drug monitoring test for patients treated for seizure disorders. Nationally, this test supports clinical decision-making for dosing, toxicity assessment and adherence monitoring; its utilization matters for both acute inpatient management and ongoing outpatient care.
Key payers reviewed in typical analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise clinical context for when the test is ordered, typical sites of service, and what the code represents in billing workflows. The publication outlines common payer considerations and benchmarks where available, highlights policy or coverage update themes relevant to laboratory therapeutic drug monitoring, and situates CPT code 80164 within routine seizure-management pathways.
This summary is intended to inform billing professionals, laboratory managers, and clinical leaders about the purpose and billing identity of the test, what to expect in payer coverage discussions, and where to look for further policy or reimbursement details. Data not available in the input are noted for specific payer policies, associated taxonomies, and related procedure mappings.
Billing Code Overview
CPT code 80164 measures the total valproic acid (dipropylacetic acid) concentration in blood. This laboratory test quantifies the amount of valproic acid, a medication commonly used to treat certain types of seizures, to assist clinicians in therapeutic drug monitoring and dosing adjustments.
Service Type: Therapeutic drug monitoring / Clinical laboratory test
Typical Site of Service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A 28-year-old outpatient with a history of generalized tonic-clonic seizures treated with valproic acid presents for routine therapeutic drug monitoring. The patient reports breakthrough dizziness and intermittent tremor since a recent dose increase. The neurology clinic orders a serum total valproic acid level to assess therapeutic range and potential toxicity. Blood is collected via standard venipuncture at the clinic’s phlebotomy station and sent to the hospital laboratory. The clinical workflow includes specimen labeling, transport to the chemistry/toxicology lab, analysis by a laboratory analyst using an appropriate validated assay to measure total valproic acid (dipropylacetic acid) concentration, result verification by a supervising laboratorian, and electronic reporting into the patient’s medical record. The provider reviews the result to confirm therapeutic levels, assess adherence, and evaluate adverse effects or need for dose adjustment.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation/reporting portion if the lab permits split billing for consultative interpretation. |
90 | Reference laboratory |