Summary & Overview
CPT 84126: Fecal Porphyrin Quantitative Analysis
CPT code 84126 denotes a laboratory assay that measures multiple porphyrin compounds in a fecal (stool) specimen. This test contributes to the diagnostic workup of disorders involving porphyrin metabolism and heme synthesis, offering clinicians biochemical data that can influence diagnostic decisions for conditions such as porphyrias and related metabolic disorders. Nationally, accurate coding and billing for specialized laboratory assays like CPT code 84126 matter for appropriate reimbursement, clinical documentation, and accurate utilization tracking of specialized diagnostic services. Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn the clinical context of the test, typical sites of service, and what to expect in payer coverage categories. The publication also summarizes common billing modifiers and outlines where data was not available in the input. The content is intended to inform coding professionals, laboratory directors, and policy analysts about the role of CPT code 84126 in clinical workflows and revenue cycle processes, and to provide a concise reference for benchmarking and policy review.
Billing Code Overview
CPT code 84126 describes a laboratory test performed by a lab analyst to evaluate the levels of multiple porphyrin compounds in a fecal (stool) specimen. The assay assesses porphyrin profiles that can support the clinical evaluation of disorders related to heme synthesis and porphyrin metabolism.
Service Type: Clinical laboratory test — quantitative porphyrin analysis
Typical Site of Service: Clinical laboratory or reference laboratory
Clinical & Coding Specifications
Clinical Context
A typical patient scenario involves a gastroenterology clinic or hospital laboratory receiving a stool specimen from a patient with unexplained abdominal pain, chronic diarrhea, dark urine, cutaneous photosensitivity, or neurological symptoms suggesting a porphyric disorder. The clinician orders fecal porphyrin testing to evaluate porphyrin compound levels when acute hepatic porphyria or other porphyrin metabolism disorders are suspected. The workflow: the clinician documents the indication and collects a fresh stool specimen (or arranges patient-collected stool per facility policy); the specimen is labeled and transported to the clinical laboratory with appropriate chain-of-custody and stability considerations. The laboratory analyst performs 84126 using chromatographic or spectrometric methods to quantify porphyrins in feces. Results are reviewed by a pathologist or laboratory director and reported to the ordering clinician, who integrates the result with biochemical and genetic testing, clinical exam, and medication history to determine diagnosis and management.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation component provided by a separate billing entity. |
TC | Technical component | Use when billing only the laboratory technical component (equipment, technician) of the test.