CPT 0111U: Praxis Extended RAS Panel for KRAS and NRAS in Colon Cancer

CPT code 0111U designates a Proprietary Laboratory Analyses (PLA) test — the Praxis™ Extended RAS Panel from Illumina — a targeted molecular assay that detects mutations in KRAS and NRAS codons from biopsy tissue. Nationally, such assays matter because KRAS/NRAS mutation status influences diagnostic characterization of colorectal tumors, eligibility for certain therapies, and downstream care decisions, contributing to precision oncology efforts across health systems.

Key payers in the coverage landscape include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. This publication summarizes clinical context for the assay, typical sites of service, and the payer coverage environment as represented by major national carriers.

Readers will learn the clinical purpose of CPT code 0111U, where the service is typically performed, and which major payers are relevant for coverage considerations. The report also outlines what types of benchmarks and policy elements to expect in payer analyses (coverage status variations, prior authorization patterns, and coding/billing considerations) and highlights the clinical implications of reporting KRAS and NRAS mutation results for colon cancer management. Data not available in the input will be flagged as such where relevant.

Billing Code Overview

CPT code 0111U is a Proprietary Laboratory Analyses (PLA) code for the Praxis™ Extended RAS Panel by Illumina. The test is a targeted gene analysis panel that assesses mutations in KRAS and NRAS codons from biopsy tissue. Mutations in these genes are clinically relevant to colon cancer and can inform tumor characterization.

Service Type: Molecular diagnostic targeted gene analysis

Typical Site of Service: Pathology or molecular diagnostics laboratory processing biopsy tissue

Data not available in the input.

Clinical Context

A 62-year-old patient with a newly diagnosed adenocarcinoma of the colon undergoes a diagnostic colonoscopy with tumor biopsy. The treating oncologist orders tumor genotyping using the Praxis™ Extended RAS Panel (Illumina) to detect activating mutations in KRAS and NRAS codons that guide anti-EGFR therapy decisions. The surgical pathology laboratory processes the formalin-fixed paraffin-embedded (FFPE) biopsy tissue, extracts DNA, and performs the targeted panel. Results are reported back to the oncology team and incorporated into therapeutic planning, such as eligibility for cetuximab or panitumumab and enrollment in genotype-directed clinical trials. Typical workflow: biopsy acquisition in an outpatient endoscopy suite or operative setting → specimen accessioning and pathology review → molecular test order placed by oncologist/pathologist → specimen sent to the performing laboratory → assay performed and report generated → result reviewed by ordering clinician and multidisciplinary team for treatment decision-making.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional interpretation component separate from the technical laboratory processing (rare for PLAs but applicable if split billing).
`51`

Taxonomy Code	Specialty	Notes
282N00000X	Molecular Pathology	Primary specialty performing and interpreting molecular oncology panels.
207K00000X	Anatomic and Clinical Pathology	Pathologists who oversee specimen diagnosis and order molecular testing.
207L00000X	Medical Oncology	Ordering clinicians who use results to guide systemic therapy.
208000000X	General Surgery	Surgeons who obtain biopsy or resection specimens and may coordinate testing.
363A00000X	Diagnostic Laboratory	Clinical laboratory specialists or laboratories performing the technical assay.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C18.9`	Malignant neoplasm of colon, unspecified	Common primary diagnosis prompting RAS mutation testing to guide targeted therapy.
`C18.0`	Malignant neoplasm of cecum	Anatomical site of colon cancer where tumor genotyping is indicated for systemic therapy planning.
`C18.2`	Malignant neoplasm of ascending colon	Tumor site associated with colorectal adenocarcinoma requiring molecular profiling.
`C18.7`	Malignant neoplasm of sigmoid colon	Site-specific colon cancer diagnosis leading to KRAS/NRAS testing.
`C20`	Malignant neoplasm of rectum	Rectal adenocarcinomas are frequently genotyped for RAS mutations when systemic therapy decisions are needed.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`0111U`	Praxis™ Extended RAS Panel — targeted gene analysis for KRAS and NRAS codons in biopsy tissue (Proprietary Laboratory Analyses code)	Primary billing code for the assay.
`88305`	Level IV surgical pathology, gross and microscopic examination	Performed on the biopsy specimen for histologic diagnosis before molecular testing; report often accompanies molecular order.
`88172`	Cytopathology, slide interpretation; diagnostic evaluation (e.g., for rapid on-site evaluation)	Used when immediate cytologic adequacy assessment is performed during biopsy to ensure sufficient material for molecular testing.
`81210`	KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) gene analysis; targeted sequence analysis	Alternate or complementary molecular code when single-gene KRAS testing is performed instead of or prior to a multigene PLA.
`81479`	Unlisted molecular pathology procedure	Used for molecular tests not otherwise specified, sometimes for novel or proprietary assays when payer requires alternate billing.

OpenPayer

Summary & Overview