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.