Summary & Overview
CPT 83631: Stool Lactoferrin Quantitative Assay
CPT code 83631 denotes a quantitative laboratory assay measuring lactoferrin in stool, used as an objective marker of intestinal inflammation. As a clinical laboratory service, this test supports diagnosis and monitoring in gastroenterology, particularly for conditions with suspected inflammatory activity. The code matters nationally because it underpins reimbursement and utilization tracking for a widely used noninvasive inflammation marker that can influence diagnostic pathways and follow-up care.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise review of clinical context for the assay, typical sites of service, and the role of the test in care pathways. The publication outlines common billing modifiers and coding relationships when available, presents national reimbursement and utilization benchmarks where present, and summarizes relevant policy and coverage considerations that affect access and billing for the assay. Additionally, the piece highlights operational considerations for laboratory and hospital billing teams when reporting this CPT code and clarifies where input data was not available.
Billing Code Overview
CPT code 83631 describes a laboratory assay in which a lab analyst performs the technical procedures to measure the quantity of lactoferrin in a stool specimen, a biomarker used to indicate inflammation of the intestinal tract. The test identifies and quantifies lactoferrin to help assess inflammatory activity in gastrointestinal disorders.
Service type: Clinical laboratory test — stool specimen analysis (quantitative lactoferrin assay)
Typical site of service: Clinical laboratory or hospital laboratory where stool specimens are processed and analyzed using immunoassay or equivalent quantitative methods.
Clinical & Coding Specifications
Clinical Context
A 34-year-old outpatient presents to a gastroenterology clinic with a 6-week history of intermittent abdominal pain, loose stools, and occasional visible blood. The clinician documents concern for inflammatory bowel disease versus infectious colitis and orders stool lactoferrin testing to detect neutrophil-derived inflammatory markers in feces. The patient is given a stool collection kit with instructions and returns the sample to the clinic laboratory the same day. The laboratory technician performs the technical assay to quantify lactoferrin level and reports a numeric result and interpretation in the laboratory information system. The clinician reviews the result to support diagnostic evaluation, triage for colonoscopy, or to guide treatment adjustments.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component if separate from the technical lab performance. |
TC | Technical component | Use when billing only the laboratory technical component (typical for this test performed by the lab). |