Loading...

    Explore
    • Policy Monitoring
    • Live Policy Feed
    • Billing Codes
    • NPI Medicare & Medicaid
    • Healthcare Providers
    • Health Insurance Payers
    • States
    • Service Lines
    • Taxonomy Codes
    Lookup tools
    • Billing Code Lookup
    • CPT Modifier Lookup
    • Provider Taxonomy Code Lookup
    • Healthcare Provider & Facility Lookup
    • Health Insurance Payer Lookup
    • Payer Contact Directory

    Policy & Benchmark Tools

    • Prior Authorization Lookup
    • Coverage Criteria Lookup
    • Timely Filing Lookup
    • Billing Code Reimbursement Rates
    • Payer Comparison Dashboard
    • Facility Comparison Dashboard
    • All tools

    Company

    • About OpenPayer
    • Data Sources
    • Trek Health
    OpenPayerby Trek Health
    LinkedInYouTube

    © 2026 Trek Health. All rights reserved.

    OpenPayer is built and maintained by Trek Health.

    v1.0.28
    OpenPayerBilling CodesTherapeutic Drug AssaysCPT cpt-80164-valproic-acid-total-blood-level
    Ask Trek AI about this page

    CPT 80164: Total Valproic Acid (Dipropylacetic Acid) Serum Level

    CPT code 80164 describes a laboratory test measuring total valproic acid (dipropylacetic acid) level in blood, a clinical chemistries service used to monitor therapeutic drug levels for seizure management; the service type is therapeutic drug monitoring (serum drug level quantification) and the typical site of service is a clinical laboratory or hospital lab where blood specimens are analyzed.

    For related coverage guidance, see recent payer policy updates: B-Hemolytic Streptococcus Testing, Human Immunodeficiency Virus (HIV) — Coverage Criteria for Testing and Resistance Assays, Hepatitis Testing (A, B, C, D) Coverage Criteria.

    Customize your policy alerts

    Sign up for cpt 80164 policy alerts

    Get alerted when payer policies referencing 80164 are released or updated.

    Monitor payer policy activity

    Receive email alerts as soon as relevant payer policies are published or updated.

    Table of contents

    Progress1 / 7

    Explore openpayer tools

    • Billing CodesCPT, HCPCS, DRG & more
    • Reimbursement RatesCommercial vs. Medicare rate reports
    • ProvidersHospitals & facilities
    • PayersPlans & market footprint
    • Taxonomy CodesNUCC specialty codes
    • ModifiersCPT modifiers & usage
    • Prior AuthorizationPA policies by payer & drug
    • Timely FilingFiling deadlines by payer
    • Coverage CriteriaMedical necessity by payer
    • Payer ContactsClaims, PA & appeals contacts
    View all tools

    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.

    Related CPT Codes

    CPT CodeDescriptionRelationship to This Procedure
    80053Comprehensive metabolic panelOften ordered alongside valproic acid level to assess liver function and electrolytes prior to dose changes.
    80307Drug assay, qualitative or quantitative, multiple drug classes; includes certain anticonvulsants (single drug class)Other drug assays may be performed concurrently for polypharmacy or toxicity evaluation.
    82043Albumin; serumSerum albumin affects free vs total valproic acid interpretation; ordered when assessing free drug levels or hypoalbuminemia.
    84484Thyroid stimulating hormone (TSH)Routine lab monitoring that may be performed during neurology follow-up visits to assess comorbid conditions.
    99000Handling and/or conveyance of specimen (if used by specific payors)Administrative/handling codes may be used per facility billing workflows when additional specimen handling is required.

    Related Modifiers

    6 rows

    ModifierDescriptionWhen to Use
    26Modifier 26 (Professional Component) identifies and bills only the professional portion of a split service — the physician’s interpretation, report, and medical judgment — when the technical…- Use CPT Modifier -26 when you are billing only the professional component (PC) of a split‑bill eligible service—i.e., you performed the physician interpretation, medical judgment and prepared a…
    90Modifier ‑90 (Reference/Outside Laboratory) indicates that a laboratory test was performed by an entity other than the treating or reporting provider. The American Medical Association defines…- Use CPT modifier -90 when a laboratory test is performed by an outside/reference laboratory (an entity other than the treating or reporting physician or qualified professional) and the claim needs…
    91Modifier 91 — “Repeat Clinical Diagnostic Laboratory Test” — is appended when the exact same CPT laboratory test is performed more than once for the same patient on the same day because serial,…- Use modifier 91 when the exact same CPT laboratory test is performed more than once on the same patient on the same date because serial or repeated testing is medically necessary to monitor…
    59Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
    52Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
    53Modifier 53 (Discontinued Procedure) signals that a surgical or diagnostic service was begun by the physician but terminated because of extenuating circumstances that threatened the patient’s…- Use modifier -53 when a physician/qualified healthcare professional has started a surgical or diagnostic procedure (e.g., anesthesia administered, incision or scope insertion) and then discontinues…

    Related Provider Taxonomies

    8 rows

    Taxonomy CodeSpecialtyNotes
    207RH0000XHematology (Internal Medicine) PhysicianAn internist with additional training who specializes in diseases of the blood, spleen and lymph. This specialist treats conditions such as anemia, cl…
    207L00000XAnesthesiology PhysicianAn anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
    208000000XPediatrics PhysicianA pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectru…
    111NR0400XRehabilitation ChiropractorRehabilitation is the discipline focused on restoring a patient's functional abilities to pre-injury or pre-disease status. Functional abilities are d…
    207ZP0102XAnatomic Pathology & Clinical Pathology PhysicianA pathologist deals with the causes and nature of disease and contributes to diagnosis, prognosis and treatment through knowledge gained by the labora…
    207RE0101XEndocrinology, Diabetes & Metabolism PhysicianAn internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with …
    207ZC0008XClinical Informatics (Pathology) PhysicianPhysicians who practice Clinical Informatics collaborate with other health care and information technology professionals to analyze, design, implement…
    363LP0222XCritical Care Pediatric Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers · Nurse Practitioner

    Related ICD-10-CM Codes

    30 rows

    ICD-10-CM CodeDescription
    E03.9Hypothyroidism, unspecified
    E10.9Type 1 diabetes mellitus without complications
    E11.9Type 2 diabetes mellitus without complications
    E78.5Hyperlipidemia, unspecified
    F05Delirium due to known physiological condition
    F11.20Opioid dependence, uncomplicated
    F19.10Other psychoactive substance abuse, uncomplicated
    F33.1Major depressive disorder, recurrent, moderate
    F41.9Anxiety disorder, unspecified
    G25.0Essential tremor

    Showing 1–10 of 30

    Related Payer Policy Updates

    Specialty: Infectious Disease1 / 3

    10 rows

    PolicyPayerEffective Date
    B-Hemolytic Streptococcus TestingOscar Health2026-10-01
    Human Immunodeficiency Virus (HIV) — Coverage Criteria for Testing and Resistance AssaysOscar Health2026-10-01
    Hepatitis Testing (A, B, C, D) Coverage CriteriaOscar Health2026-10-01
    Lyme Disease Testing Coverage CriteriaOscar Health2026-10-01
    Pathogen Panel TestingOscar Health2026-10-01
    Diagnostic Testing of Common Sexually Transmitted InfectionsOscar Health2026-10-01
    Testing for Diagnosis of Active or Latent TuberculosisOscar Health2026-10-01
    Testing for Vector-Borne InfectionsOscar Health2026-10-01
    Coronavirus Testing in the Outpatient SettingOscar Health2026-10-01
    Human Immunodeficiency Virus (HIV)blue cross blue shield - louisiana2026-09-15

    Related Codes

    CPT-80143-ACETAMINOPHEN-QUANTITATIVE-SERUM-ASSAY

    CPT 80143: Acetaminophen Quantitative Assay

    CPT-80145-ADALIMUMAB-LEVEL-ASSAY-THERAPEUTIC-DRUG-MONITORING

    CPT 80145: Adalimumab Quantitative Drug Level Assay

    CPT-80150-AMIKACIN-QUANTITATIVE-ASSAY-THERAPEUTIC-DRUG-MONITORING

    CPT 80150: Amikacin Quantitative Serum Level

    CPT-80151-AMIODARONE-QUANTITATIVE-SERUM-ASSAY

    CPT 80151: Amiodarone Quantitative Drug Level Assay

    CPT-80155-CAFFEINE-LEVEL-TESTING

    CPT 80155: Caffeine Level Quantification

    CPT-80156-CARBAMAZEPINE-TOTAL-LEVEL-LAB-ASSAY

    CPT 80156: Carbamazepine Total Level (Serum)

    CPT-80157-FREE-CARBAMAZEPINE-ASSAY

    CPT 80157: Free Carbamazepine Quantitative Assay

    CPT-80158-CYCLOSPORINE-QUANTITATIVE-ASSAY-LAB

    CPT 80158: Cyclosporine Quantitation, Laboratory

    CPT-80159-CLOZAPINE-LEVEL-ASSAY-THERAPEUTIC-DRUG-MONITORING

    CPT 80159: Clozapine Level Measurement

    CPT-80161-CARBAMAZEPINE-EPOXIDE-QUANTITATIVE-ASSAY

    CPT 80161: Carbamazepine 10,11-Epoxide Level, Quantitative

    Showing 1–10 of 87

    • More pages

    Frequently Asked Questions

    References

    1. 1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
    2. 2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
    3. 3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.
    Published by

    Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

    Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.