CPT 80235 Lacosamide Assay Reimbursement

CPT code 80235 designates a quantitative laboratory assay that measures lacosamide concentration in a patient specimen. As a pharmacologic monitoring test for an antiepileptic medication used in adjunctive therapy for partial‑onset seizures, this code supports clinical decisions about dosing, adherence, and potential toxicity. Nationally, therapeutic drug monitoring codes like 80235 are important for outpatient and inpatient epilepsy management and for laboratories providing specialized mass spectrometry or immunoassay testing.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context, common service settings, and publication‑level benchmarks where available. The report also outlines typical payer coverage patterns, common modifiers used with laboratory services, and operational considerations for labs submitting claims for therapeutic drug monitoring of antiepileptic agents.

This summary is organized to provide a quick reference for clinicians, laboratory managers, and revenue cycle staff: what the code represents, why it matters to patient care, and which payers are relevant. Data not available in the input are noted where applicable.

Billing Code Overview

CPT code 80235 describes a clinical laboratory service in which a lab analyst performs a quantitative measurement of lacosamide in a patient specimen. Lacosamide is an antiepileptic medication commonly used as part of combination therapy to treat partial‑onset seizures.

Service type: Therapeutic drug monitoring / quantitative laboratory assay
Typical site of service: Clinical laboratory or hospital laboratory (specimen processing and analysis)

Clinical Context

A 32-year-old patient with partial-onset seizures managed on lacosamide presents for routine therapeutic drug monitoring after a recent dose change and intermittent breakthrough focal seizures. A clinician orders a serum lacosamide level to assess adherence and therapeutic concentration. A phlebotomy technician collects a blood sample in the outpatient laboratory or hospital inpatient setting; the specimen is sent to the clinical chemistry laboratory. A laboratory analyst performs the quantitative assay for lacosamide (CPT 80235) using validated methods (e.g., LC-MS/MS or immunoassay), documents the assay result in the laboratory information system, and the result is routed to the ordering neurologist. Typical sites of service include outpatient hospitals, independent clinical laboratories, and hospital inpatient laboratories. Turnaround time varies by clinical need: routine levels within 24–72 hours, stat levels within hours. The test is used to confirm therapeutic dosing, evaluate suspected toxicity, assess adherence, and guide medication adjustments when combined with clinical assessment and other monitoring (e.g., drug–drug interactions).

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	When billing separates the professional interpretation or consultation from the technical component of the lab service (rare for quantitative lab assay but used if a pathologist provides a consultative interpretation).

Taxonomy Code	Specialty	Notes
207RH0000X	Clinical Laboratory Molecular Pathology	Laboratories performing quantitative drug assays, including LC-MS/MS.
207L00000X	Clinical Laboratory	General clinical laboratory services and medical laboratory scientists.
2080P0207X	Neurology	Ordering clinicians who manage antiepileptic therapy and interpret levels.
363A00000X	Clinical Pharmacology	Clinical pharmacists who interpret therapeutic drug monitoring and advise dosing.
207LP2900X	Toxicology	Reference toxicology laboratories that perform quantitative drug levels.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G40.209`	Localization-related (focal)(partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, unspecified, not intractable	Common indication for lacosamide therapy and for monitoring serum levels to assess seizure control and dosing.
`G40.309`	Generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus	Lacosamide may be used adjunctively in some focal seizure disorders that are part of broader epilepsy management.
`T42.7X5A`	Poisoning by other antiepileptic and sedative-hypnotic drugs, accidental (initial encounter)	Relevant when assessing suspected toxicity or overdose of lacosamide.
`Z79.899`	Other long term (current) drug therapy	Indicates chronic medication use warranting periodic therapeutic drug monitoring.
`R56.9`	Unspecified convulsions	Symptom prompting measurement of antiepileptic drug levels to evaluate cause and adherence.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80307`	Drug assay, qualitative or semiquantitative, single drug class method (e.g., immunoassay), urine	May be performed alongside serum quantification to screen for multiple drugs or adherence in urine when clinical context requires broader toxicology screening.
`80311`	Drug confirmation, quantitative, by definitive technology (e.g., GC/MS, LC/MS/MS), single drug	Used for definitive confirmation of drug levels or when a different method is required; similar analytical platforms may be used for lacosamide quantification.
`80500`	Drug assay, quantitative, single drug (e.g., serum, plasma)	Generic quantitative drug assay category; related when labs bill a specific quantitative assay for therapeutic drug monitoring.
`36415`	Collection of venous blood by venipuncture	Often performed immediately prior to the assay as the specimen collection procedure.
`99000`	Handling and/or conveyance of specimen (used historically)	Administrative or specimen handling codes in some billing systems relate to logistics of specimen transport to the performing laboratory.

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Summary & Overview

CPT 80235: Lacosamide Quantitative Assay