Summary & Overview
CPT 86431: Rheumatoid Factor (RF) Serology Test
CPT code 86431 denotes a laboratory serology test that quantifies rheumatoid factor (RF) in patient blood. This immunologic assay supports clinical evaluation of suspected rheumatoid arthritis and other autoimmune or inflammatory disorders; it is widely used across outpatient and inpatient laboratory settings. Nationally, RF testing remains a common diagnostic adjunct that influences rheumatology referrals, diagnostic workups, and treatment planning.
Key payers discussed for coverage and billing patterns include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of code purpose and clinical context, payer coverage considerations, and the typical settings where the service is delivered. The analysis highlights common reimbursement factors and coding practice issues tied to serologic lab testing.
This publication provides benchmarks for utilization and payment practices, summarizes relevant policy or coverage updates where available, and situates CPT code 86431 within routine laboratory workflows. Data not available in the input are noted where applicable.
Billing Code Overview
CPT code 86431 describes a laboratory assay performed by a lab analyst to measure the level of rheumatoid factor (RF) in a patient’s blood. This test is a serologic diagnostic service used to help evaluate suspected rheumatoid arthritis and other autoimmune or inflammatory conditions.
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Service type: Laboratory serology test
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Typical site of service: Clinical laboratory or hospital laboratory setting
Clinical & Coding Specifications
Clinical Context
A typical patient is a 52-year-old woman presenting to a primary care clinic or rheumatology office with a 3-month history of joint pain, morning stiffness lasting more than 30 minutes, and progressive swelling of small hand joints. The clinician performs a focused musculoskeletal exam and orders laboratory testing to evaluate for inflammatory arthropathy. A venous blood sample is collected in the office or at an outpatient laboratory. The specimen is sent to a clinical laboratory where the lab analyst performs a serologic assay to measure rheumatoid factor (86431). Results are reviewed by the ordering clinician to help support or exclude a diagnosis of rheumatoid arthritis, to correlate with other serologies (for example anti-CCP), inflammatory markers (ESR, CRP), and imaging, and to guide further rheumatology referral and management. Typical sites of service include outpatient clinic, independent clinical laboratory, hospital outpatient laboratory, or ambulatory surgery center when testing is part of a preoperative evaluation. Turnaround time depends on lab workflow; reflex testing or repeat testing may occur based on abnormal values.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional component for the laboratory interpretation if separate from technical testing (rare for ). |