What this page covers
Gastroenterology billing services manage the claim mechanics specific to GI: screening versus diagnostic colonoscopy coding, paired anesthesia and facility claims, infusion billing, and biologic prior authorization. The screening distinction carries the most patient-facing risk, because a miscoded screening sends a bill for a visit the patient expected to be free. The paired claims carry the most denial risk, because the professional, anesthesia, and ASC claims for one procedure must tell the same story. Flexbone runs this work with agents inside gGastro, Provation, and your billing system, from eligibility through denial follow-up.
How do screening and diagnostic colonoscopy modifiers work?
The modifier tells the payer the procedure began as a screening, which preserves the preventive benefit. Medicare screening colonoscopy is billed with G0121 for average risk or G0105 for high risk. When the physician finds and removes a polyp, the procedure is coded with the CPT therapeutic code, such as 45380 or 45385, plus modifier PT to show it began as a screening. Commercial plans use modifier 33 for the same purpose. Omit the modifier and the claim adjudicates as diagnostic, cost sharing applies, and the patient gets a bill for a visit they expected to be covered in full. Those calls and refunds are avoidable. The gastroenterology billing explainer covers the coding logic in more depth.
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How are anesthesia, infusion, and biologic claims billed in GI?
One colonoscopy can produce three claims: the gastroenterologist's professional claim, the anesthesia claim, and the ASC facility claim. All three must agree on the procedure, the diagnosis, and the screening status, because the payer adjudicates each one separately. Anesthesia for a screening colonoscopy bills under its own code, 00812, and keeps the preventive status only when its coding matches the surgical claim. On the infusion side, IBD biologics such as infliximab and vedolizumab bill as a drug J-code plus administration codes 96413 and 96415. They carry prior authorization with step therapy documentation before the first infusion. The GI and general surgery PA page covers the authorization workflow.
What are the common gastroenterology denial patterns?
GI denials cluster in four places. Screening reclassification: the claim lost its preventive status and the patient balance is disputed. Frequency edits: a surveillance colonoscopy performed sooner than the interval the plan covers. Missing authorization: diagnostic endoscopy, capsule endoscopy, or a biologic infusion delivered before the approval posted. Bundling edits: endoscopy codes from the same session reduced under the multiple endoscopy rules. Flexbone reads the 835 remittance, maps the CARC and RARC codes, corrects and resubmits the mechanical failures, and assembles documentation for the appeals that need it.
How does Flexbone run gastroenterology billing?
Flexbone deploys browser and voice agents across the GI revenue cycle rather than staffing a coding desk. Agents verify eligibility with a 270/271 check before the visit, confirm the screening benefit, submit and track the endoscopy and biologic authorizations, follow up claims, and work the denial queue inside gGastro, Provation, or your billing system. The front-office side, procedure scheduling and the bowel-prep calls that protect the endoscopy schedule, is covered on the AI for gastroenterology page. Results write back to the chart with an audit trail, and exceptions route to your billers with context.