CPT 0535U: PFAS Testing (PFASure®FT) in Plasma or Serum

CPT code 0535U is a PLA-level laboratory code for PFAS Testing & PFASure®FT from National Medical Services (NMS Labs), a quantitative assay measuring per- and polyfluoroalkyl substances such as PFOA and PFOS in plasma or serum. This code identifies a single proprietary test used to document individual PFAS exposure and supports clinical and public health evaluation of toxic environmental exposures. Nationally, PFAS testing has relevance for environmental health monitoring, occupational exposure assessment, and patient counseling when elevated exposures are suspected.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of coverage landscape and payer inclusion, the clinical context for ordering PFAS assays, and what the code represents for billing and lab reporting. The publication outlines typical service settings (clinical and reference laboratories), the specialized nature of PLA coding, and the implications of using a manufacturer- or lab-specific code for claims processing.

This summary provides concise guidance on where CPT code 0535U fits within laboratory service lines, why unique PLA codes matter for traceability and reimbursement workflows, and which audiences—laboratories, clinicians ordering PFAS testing, and payers—are most directly affected. Data not available in the input will be noted in relevant sections.

Billing Code Overview

CPT code 0535U is a Proprietary Laboratory Analyses (PLA) code that applies only to a single, unique laboratory test: PFAS Testing & PFASure®FT from National Medical Services (NMS Labs). The test measures concentrations of perfluoroalkyl substances (PFAS), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), in plasma or serum to provide quantitative data for assessing individual exposure to these synthetic chemicals.

Service type: Laboratory — specialty toxicology testing (proprietary PFAS assay)

Typical site of service: Clinical laboratories or reference laboratories where blood specimens (plasma or serum) are collected, processed, and analyzed. Data not available in the input.

Clinical Context

A typical patient scenario involves an adult or child with possible environmental exposure to per- and polyfluoroalkyl substances (PFAS) due to living near industrial sites, contaminated drinking water, occupational exposure (eg, firefighter, chemical plant worker), or concerns raised by public health screening. The clinician documents exposure history and orders quantitative serum or plasma PFAS testing using the proprietary PFASure®FT assay performed by National Medical Services (NMS Labs). Blood is collected (serum or plasma) during an outpatient lab visit or hospital phlebotomy session and shipped to NMS Labs per specimen handling instructions. Results report concentrations of individual PFAS analytes (eg, PFOA, PFOS) to inform exposure assessment, occupational health follow-up, public health investigations, or longitudinal monitoring of known exposure. Typical sites of service are outpatient laboratory collection centers, hospital outpatient phlebotomy, occupational health clinics, or public health screening events. Service type: Proprietary Laboratory Analysis (PLA) for quantitative PFAS measurement reported under 0535U.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier specified (placeholder)	Use when no specific modifier applies to the claim as submitted.

Taxonomy Code	Specialty	Notes
`208D00000X`	Diagnostic Laboratory	Laboratories that perform specialized toxicology and environmental chemistry testing, including PFAS assays.
`207R00000X`	Occupational Medicine	Clinicians managing work-related exposure assessments and ordering PFAS testing for employees.
`207L00000X`	Environmental Medicine	Providers focused on environmental exposures and community health screening programs.
`207Q00000X`	Emergency Medicine	ED providers may order PFAS testing during acute exposure evaluation when indicated.
`1835S0206X`	Public Health Laboratory	Public health and government labs coordinating population exposure surveillance and confirmatory testing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`Z77.121`	Contact with and (suspected) exposure to per- and polyfluoroalkyl substances (PFAS)	Direct exposure code used when PFAS exposure is known or suspected and triggers quantitative serum testing.
`Z77.110`	Contact with and (suspected) exposure to lead	Example of environmental exposure cluster coding when multiple exposures are evaluated; may coexist with PFAS assessment.
`Z57.9`	Occupational exposure, unspecified	Used when occupational exposure is suspected but not otherwise specified; supports testing in work-related contexts.
`Z91.89`	Other specified personal risk factors, not elsewhere classified	Used for personal history or risk factors prompting environmental exposure testing when specific codes are not available.
`R68.89`	Other general symptoms and signs	Used when nonspecific symptoms attributable to environmental exposure are present and testing is ordered as part of diagnostic evaluation.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`81002`	Urinalysis, non-automated, without microscopy	Urine testing sometimes performed concurrently for environmental exposure screening or baseline toxicology panels.
`81000`	Urinalysis, by dipstick or tablet reagent; routine, non-automated	Point-of-care screening that may accompany exposure evaluation prior to definitive PFAS serum testing.
`36415`	Collection of venous blood by venipuncture	Blood collection procedure required to obtain serum or plasma for the PFASure®FT assay.
`99000`	Handling and/or conveyance of specimen for transfer from physician office to laboratory	Applies when specimen transport services are billed separately for off-site testing at a reference lab.
`80500`	Drug assay, presumptive, any number of drug classes; any number of specimens	Toxicology panels that may be ordered alongside PFAS testing when broader exposure/toxicant assessment is performed.

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Summary & Overview