Summary & Overview
CPT 0524U: sFlt‑1/PlGF Ratio Assay for Preeclampsia Diagnosis
CPT code 0524U designates a Proprietary Laboratory Analyses (PLA) test for the PreClaraTMRatio, quantifying the ratio of soluble fms–like tyrosine kinase-1 (sFlt–1) to placental growth factor (PlGF) via immunoassay. This CPT PLA code is specific to Thermo Fisher Scientific's PreClaraTMRatio assay and is used to aid in the diagnosis of preeclampsia by assessing biomarkers associated with placental vascular function. Nationally, the code matters because targeted biomarker assays for preeclampsia are increasingly used to stratify risk, inform clinical decision-making, and influence use of maternal-fetal monitoring resources.
Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose of the test, payer coverage context, common billing modifiers, and operational considerations for specimen type and typical site of service. The publication also summarizes expected content areas such as benchmark billing practices, relevant policy or coverage trends for proprietary lab tests, and clinical context for interpretation of an sFlt‑1/PlGF ratio. Data not available in the input will be identified where applicable.
Billing Code Overview
CPT code 0524U is a Proprietary Laboratory Analyses (PLA) code assigned specifically to the PreClaraTMRatio (sFlt–1/PlGF) test from Thermo Fisher Scientific. The assay measures the ratio of soluble fms–like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) using an immunoassay on a serum or plasma sample to aid in the diagnosis of preeclampsia.
Service type: Proprietary laboratory diagnostic immunoassay
Typical site of service: Clinical laboratory or hospital laboratory
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A pregnant patient in the second or third trimester presents to an obstetric clinic or hospital with new-onset hypertension, proteinuria, or symptoms concerning for preeclampsia such as severe headache, visual changes, epigastric pain, or rapid edema. The ordering clinician (maternal-fetal medicine specialist, obstetrician-gynecologist, or labor and delivery physician) requests the PreClaraTMRatio (sFlt–1/PlGF) immunoassay to aid in the diagnostic evaluation and short-term risk stratification for preeclampsia.
The clinical workflow: the patient undergoes venipuncture for serum or plasma collection in an outpatient clinic, antepartum testing unit, emergency department, or inpatient labor and delivery unit. The specimen is labeled and sent to the performing laboratory (or the manufacturer's designated lab) for analysis using the proprietary Thermo Fisher Scientific assay. Results are reported to the ordering clinician and incorporated into clinical decision-making regarding monitoring intensity, timing of delivery, need for transfer to a higher level of maternal-fetal care, or outpatient follow-up. Billing for this proprietary laboratory analysis is reported using 0524U for the specific PreClaraTMRatio test.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier — standard reporting | Use when no additional modifier applies to the professional or technical components. |