Summary & Overview
CPT 0095U: Esophageal String Test (ELISA biomarkers)
CPT code 0095U designates a Proprietary Laboratory Analyses (PLA) test for the Esophageal String Test™ (EST) from EnteroTrack™ Labs. The EST is a minimally invasive diagnostic assay that collects esophageal proteins on a swallowed string and uses ELISA to quantify two biomarkers, with an algorithmic output estimating the probability of active eosinophilic esophagitis. As a PLA code, 0095U applies to a single unique test tied to a specific manufacturer or laboratory, which has implications for billing, coding transparency, and payer coverage decisions nationwide.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for the EST, how the PLA designation affects code use and reporting, and what to expect in payer interactions. The publication summarizes available benchmarks and coverage patterns where present, highlights policy considerations relevant to proprietary assays, and outlines the service and typical site of service for clinical teams and billing staff.
The analysis aims to inform clinical administrators, laboratory directors, and coding professionals about the code's intended use, payer landscape, and the operational setting for test administration and processing. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 0095U is a Proprietary Laboratory Analyses (PLA) code for the Esophageal String Test™ (EST) developed by EnteroTrack™ Labs. The test analyzes esophageal proteins collected on a swallowed string using enzyme–linked immunosorbent assays (ELISA) to measure two biomarkers associated with eosinophilic esophagitis and applies an algorithm to predict the probability of active disease.
Service type: Laboratory diagnostic test using a minimally invasive sample collection (swallowed string) with ELISA-based biomarker analysis and algorithmic interpretation.
Typical site of service: Outpatient clinic or ambulatory care setting where the Esophageal String Test™ can be administered and specimen processed by EnteroTrack™ Labs or the manufacturer's designated laboratory.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adolescent or adult with symptoms suggestive of eosinophilic esophagitis (EoE) — including persistent dysphagia, food impaction history, odynophagia, or refractory heartburn despite proton pump inhibitor therapy. The Esophageal String Test™ (EST) from EnteroTrack™ Labs is ordered by a gastroenterologist to nonendoscopically assess esophageal mucosal biomarkers when endoscopy is being avoided or to monitor disease activity between endoscopies. The patient swallows a capsule attached to a string; the string is retrieved after a dwell time and sent to EnteroTrack™ Labs. Laboratory processing uses enzyme–linked immunosorbent assays (ELISA) on proteins captured from the string and an algorithm to report the probability of active EoE. Typical workflow: outpatient clinic visit with informed consent, administration of the EST capsule and instructions, string retrieval in clinic or by patient per protocol, specimen packaging and shipment to the proprietary lab, laboratory analysis using ELISA and algorithmic interpretation, and result reporting to the ordering provider for clinical correlation and potential treatment adjustment. Typical site of service is outpatient gastroenterology clinic or ambulatory procedure center. Service type: proprietary laboratory analysis (PLA) performed by EnteroTrack™ Labs as a specialized diagnostic laboratory test.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when a physician performs and bills the professional interpretation separate from the lab technical component, if applicable. |
TC | Technical component | Use when billing for the laboratory technical component only, commonly by the performing laboratory. |
52 | Reduced services | Use if the specimen collection or testing is partially reduced from standard protocol. |
53 | Discontinued procedure | Use if the string test was started but aborted for valid clinical reasons. |
59 | Data not available in the input. | Data not available in the input. |
QK | Medical direction of two, three, or four assistants by the physician or other qualified health care professional | Use when applicable to staffing during in-clinic string placement or retrieval under physician direction. |
QX | Modifier for assistant-at-surgery when requirements met | Use when a qualified assistant is present and meets billing criteria for the service setup. |
QY | Medical necessity modifiers for assistant services | Use per payor policy if assistant-level services meet medical necessity documentation. |
AD | Claim Adjustment Group Code (payer-specific) | Use per payer instruction when needed for claim reporting adjustments. |
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services for Medicare beneficiaries | Use when the EST is performed or supervised by these practitioners per Medicare rules. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 208000000X | Gastroenterology | Gastroenterologists commonly order and interpret EST results and coordinate collection. |
| 207RC0000X | Internal Medicine - Gastroenterology | Hospital-based or clinic internists with GI focus who manage EoE patients. |
| 363L00000X | Clinical Laboratory | Reference laboratory personnel performing ELISA analysis and reporting results. |
| 367500000X | Nurse Practitioner | NPs in gastroenterology clinics who may place or retrieve the string and manage follow-up. |
| 274M00000X | Physician Assistant | PAs who assist in clinic-based specimen collection and patient counseling. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
K20.0 | Oesophagitis due to reflux | Differentiates reflux-related esophageal inflammation from EoE in symptomatic patients. |
K20.9 | Esophagitis, unspecified | Non-specific esophagitis listed when initial diagnosis is unclear pending EST or biopsy. |
K52.2 | Allergic and dietetic gastroenteritis and colitis | Represents atopic conditions that commonly coexist with EoE and may influence testing. |
J45.909 | Unspecified asthma, uncomplicated | Asthma is an atopic comorbidity frequently present in patients with EoE. |
R13.10 | Dysphagia, unspecified | A common presenting symptom prompting diagnostic evaluation with EST. |
T18.128A | Food bolus obstruction of esophagus, initial encounter | History of food impaction is a common clinical trigger for EoE evaluation. |
K21.9 | Gastro-esophageal reflux disease without esophagitis | Clinical differential diagnosis when assessing esophageal symptoms with EST. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0095U | Esophageal String Test™ (EST) from EnteroTrack™ Labs; ELISA on esophageal proteins with algorithm to predict active eosinophilic esophagitis | Proprietary PLA code for the specific laboratory analysis described; primary test code for the service. |
43239 | Esophagogastroduodenoscopy, flexible, transoral; diagnostic, with or without collection of specimen(s) by brushing or washing | Performed when endoscopic assessment and mucosal biopsies are indicated; used before or instead of EST when direct visualization is required. |
43251 | Esophagogastroduodenoscopy, flexible, transoral; with biopsy, single or multiple | Endoscopic biopsy is the standard diagnostic comparator for EoE and may be performed alongside or following EST for confirmation. |
91000 | Flexible endoscopic biopsy processing and interpretation (pathology) | Pathology processing of esophageal biopsy specimens is commonly performed when endoscopy with biopsy is done in the same clinical pathway. |
99000 | Data not available in the input. | Data not available in the input. |