Multi-physician gastroenterology practices lose $140,000 to $220,000 a year to billing errors, according to medical billing company ProMBS. The company says the losses come mostly from miscoding, not care quality.
The losses come mainly from undercoded colonoscopy conversions, missed codes and modifier errors, the company said in a 2026 GI billing guide.
Here are the codes it flagged as most often miscoded:
- 45380 (colonoscopy with biopsy): Billed as 45378, the diagnostic-only code, even when tissue was taken.
- 45385 (snare polypectomy): One of the highest-value GI codes, and a costly miss when it’s replaced with 45378.
- 45381 (directed submucosal injection): Often missed when a lesion is injected to lift it before removal.
- 45382 (control of bleeding): Lost when coders assume bleeding control was incidental.
- 45386 (balloon dilation): Often bundled incorrectly.
- G0105 and G0121: Medicare screening codes for high-risk and average-risk patients. Using the wrong one triggers a denial.
- 43239 (EGD with biopsy): Undercoded as 43235, the diagnostic EGD code.
- 43254 (EGD with endoscopic mucosal resection): Coders often default to simpler codes out of caution.
- ERCP codes 43260 through 43278: A major source of lost revenue at practices with high pancreaticobiliary volume when not all interventions are captured.
The company also said E/M visits for complex patients, such as those with IBD on biologics, are often coded at lower levels because medical decision-making isn’t fully documented.
At the Becker’s 32nd Annual Meeting: The Business and Operations of ASCs, taking place October 29-31 in Chicago, ASC leaders, surgeons and healthcare executives will explore strategies to drive growth, enhance operational performance, navigate reimbursement challenges and prepare for the future of ambulatory surgery. Apply for complimentary registration now.
