Summary & Overview
CPT 0421U: Colosense™ Fecal Molecular Colorectal Cancer Risk Test
CPT code 0421U denotes a Proprietary Laboratory Analyses (PLA) test reserved for Colosense™ by Geneoscopy Inc., a fecal molecular diagnostic that quantifies RNA expression of eight genes plus fecal hemoglobin and uses an algorithm to report positive or negative colorectal cancer risk. As a PLA code, 0421U applies only to this single manufacturer’s test, which matters for coding precision, payer recognition, and billing audit clarity nationwide. Nationally, PLA codes like 0421U are tracked for utilization, coverage determinations, and clinical validation as they represent proprietary assays that can influence screening pathways for colorectal cancer.
Key payers covered in typical analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical purpose and laboratory service model, payer coverage considerations, available benchmarking and reimbursement context, and implications for coding and billing workflows. The publication outlines how the assay’s algorithmic result and unique PLA designation affect documentation, claims reporting, and interactions with laboratory and payer processes. Data limitations: Data not available in the input on utilization volumes, reimbursement amounts, and payer-specific coverage policies.
Billing Code Overview
CPT code 0421U is a Proprietary Laboratory Analyses (PLA) code specific to a single commercial test: Colosense™ from Geneoscopy Inc. The test is a fecal-based molecular assay that measures RNA expression of eight named genes and assesses fecal hemoglobin level. An integrated algorithmic analysis of those inputs generates a reported risk result of positive or negative for colorectal cancer.
Service type: Laboratory — molecular diagnostic stool assay
Typical site of service: Clinical laboratory or reference laboratory with receipt of patient fecal specimen; sample collection may occur at home with subsequent lab processing
Clinical & Coding Specifications
Clinical Context
A 58-year-old average-risk patient with intermittent rectal bleeding and a family history of colorectal cancer requests noninvasive screening. A primary care physician orders the Colosense™ fecal test (0421U) provided by Geneoscopy Inc. The patient collects a stool sample at home using the manufacturer kit and returns it to the designated laboratory or mails it per kit instructions. The laboratory performs RNA expression analysis of the eight specified genes and measures fecal hemoglobin, runs the proprietary algorithm, and issues a report indicating risk of colorectal cancer positive or negative. Results are routed to the ordering clinician who documents test interpretation, discusses risk and next steps (for example, colonoscopy referral if positive), and files the report in the medical record. Typical site of service is outpatient ambulatory care with sample collection at home and analysis in a clinical laboratory specializing in molecular diagnostic testing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default primary identifier (no modifier) | Use when no specific modifier applies to the laboratory PLA service |
26 | Professional component | Use if reporting only the professional component (interpretation) when separated from technical component |
TC | Technical component | Use when reporting only the technical component (laboratory analysis) separate from professional interpretation |
52 | Reduced services | Use if the laboratory service was partially reduced or limited compared to the full test |
53 | Discontinued procedure | Use if testing was started but discontinued prior to completion for valid clinical reasons |
59 is not listed in input | Data not available in the input. | Data not available in the input. |
62 | Two surgeons (not typically applicable to lab) | Rarely used; not generally applicable to 0421U but included among available modifiers |
78 | Unplanned return to the operating/procedure room | Not applicable to a lab PLA except in exceptional institutional billing situations |
80 | Assistant surgeon | Not applicable to this laboratory test; included in modifier list provided |
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery | Not applicable to this lab-based test |
QK | Medical direction of two, three, or four concurrent anesthesia procedures | Not applicable to PLA testing |
QX | CRNA service: CRNA with medical direction | Not applicable to PLA testing |
QY | Medical direction of one CRNA by an anesthesiologist | Not applicable to PLA testing |
TC | Technical component | Use when the laboratory reports only the technical analysis and another provider reports interpretation (same as above) |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 208000000X | General Practice | Primary care clinicians ordering noninvasive colorectal screening tests |
| 207Q00000X | Gastroenterology | Specialists who may order the test for screening or diagnostic triage |
| 363L00000X | Clinical Laboratory | Laboratories performing the molecular and hemoglobin analysis |
| 207RP1001X | Colorectal Surgery | Surgeons who may receive results to guide referral for colonoscopy or surgery |
| 207K00000X | Internal Medicine | Internists managing screening and follow-up of results |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
R19.5 | Other fecal abnormalities | Symptom prompting fecal testing when patients report abnormal stool findings |
R19.7 | Diarrhea, unspecified | Symptom that may prompt evaluation including fecal testing in appropriate clinical context |
K92.1 | Melena | Evidence of gastrointestinal bleeding that may lead clinicians to order fecal hemoglobin testing |
Z12.11 | Encounter for screening for malignant neoplasm of colon | Standard screening encounter where a noninvasive fecal test like 0421U may be ordered |
Z80.0 | Family history of malignant neoplasm of digestive organs | Family history that increases screening vigilance and may prompt ordering of advanced noninvasive tests |
R10.9 | Abdominal pain, unspecified | Common presenting symptom that can lead to diagnostic evaluation including stool-based testing |
K63.5 | Polyp of colon | Relevant when monitoring patients with known polyps or assessing recurrence risk via noninvasive testing |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0421U | Colosense™ (Geneoscopy Inc.): fecal RNA expression assay of specified genes and fecal hemoglobin with algorithmic analysis to report colorectal cancer risk | Primary Proprietary Laboratory Analysis (PLA) code describing the test itself |
82270 | Immunoassay for fecal hemoglobin (fecal occult blood), qualitative or quantitative | May be performed separately or as a comparator; fecal hemoglobin measurement is a component of 0421U |
88342 | Immunohistochemistry, per specimen; initial single antibody stain | Not directly part of fecal PLA but commonly billed in pathology workflows when tissue biopsy follows a positive noninvasive test |
45378 | Colonoscopy, flexible; diagnostic, with or without collection of specimen(s) by brushing or washing | Common follow-up diagnostic procedure when 0421U returns positive or indicates increased risk |
G0328 | Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk | Related screening colonoscopy code used in workflow when noninvasive screen suggests need for colonoscopy |