A screening colonoscopy that finds a polyp is a different claim. A colonoscopy with biopsy is a different claim. Every combination has specific CPT, modifier, and diagnosis pairing requirements. We know them.
We see the same patterns across gastroenterology groups. The leaks are specific, recurring, and fixable with coding discipline and payer-aware claim construction.
Not a complete list. A representative slice of the codes that drive revenue and denials for gastroenterology practices.
| Code | Description | Profile |
|---|---|---|
| 45378 | Diagnostic colonoscopy | High volume |
| 45380 | Colonoscopy with biopsy | Modifier-sensitive |
| 45385 | Colonoscopy with polyp removal by snare | Denial-prone |
| G0105 | Colorectal cancer screening, high risk | High volume |
| G0121 | Colorectal cancer screening, average risk | Modifier-sensitive |
| 43239 | Upper GI endoscopy with biopsy | Denial-prone |
| 43260 | ERCP diagnostic | High volume |
| J3380 | Vedolizumab injection | Modifier-sensitive |
Modifier PT and 33 applied correctly when screening converts to diagnostic. Multiple endoscopy rules applied to the secondary procedure. ASC facility claim filed in parallel with professional. Biologic prior auth tracked across payer-specific step therapy requirements.
Pattern we see. Screening colonoscopy billed as diagnostic without modifier 33, medical necessity denials on younger patients without family history documentation, and biologic infusion denials for incomplete step therapy documentation.
How we fix it. Every denial is logged against its CARC/RARC code and routed to a coder who owns the appeal. We rebuild the claim with the documentation the payer is actually asking for, not a generic reconsideration letter. Recovery rate on appealable gastroenterology denials averages above 60 percent.
A written 30-day diagnostic. Dollar figures against every finding. No obligation.