CPT code 80143 identifies a quantitative laboratory assay measuring acetaminophen concentration in patient specimens (commonly serum). This code is used when the laboratory performs the technical testing to determine drug levels, which is clinically important for assessing overdose risk, guiding treatment decisions such as antidote administration, and monitoring therapeutic exposure. Nationally, toxicology and therapeutic drug monitoring are routine components of emergency, inpatient, and outpatient care pathways.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for acetaminophen testing, typical sites where the service is provided, and the kinds of benchmarks and policy considerations commonly associated with laboratory drug assays. The publication outlines reimbursement and billing practice benchmarks, common modifiers, and payer coverage considerations where available, along with notes on coding relationships and clinical utility.

This summary provides clinicians, billers, and policy stakeholders with the essential facts about CPT code 80143, the role of acetaminophen level testing in patient care, and what to expect when reviewing coverage and billing guidance for quantitative toxicology assays.