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Gastroenterology Billing: Screening and Diagnostic Endoscopy Coded Right
Colonoscopy, EGD and In-Office GI Care
GI practices perform a high volume of endoscopic procedures, and the line between screening and diagnostic colonoscopy changes what the patient owes and how the claim must be coded. Billing Care Assistant handles gastroenterology billing so procedures, anesthesia, pathology and office visits are billed correctly and patients are not surprised by their bills.
Common GI Billing Problems We Fix
| Billing problem | Why it costs you | How we fix it |
|---|---|---|
| Screening colonoscopy turns diagnostic | Removing a polyp changes the codes, modifiers and the patient’s cost share | We use modifier PT for Medicare or 33 for commercial plans so screening benefits still apply |
| Medicare screening codes not used | Medicare uses G0105 and G0121 for screening colonoscopy | We code Medicare screenings with the right G-code and frequency rules |
| Wrong code for polyp removal | Snare, biopsy forceps and ablation each have their own codes | We code each technique from the procedure report |
| Colonoscopy after a positive stool test | Many payers now treat these as screening, but rules vary | We code follow-up colonoscopies based on each payer’s policy |
| Anesthesia not lined up with the procedure | Anesthesia for endoscopy has its own codes and coverage rules | We coordinate anesthesia billing with the procedure codes |
GI Codes We Handle
Endoscopy and office care
We code screening and diagnostic colonoscopy (45378-45398 and G0105, G0121), upper endoscopy (43235-43270), flexible sigmoidoscopy, ERCP, capsule endoscopy (91110), esophageal and anorectal motility studies, hemorrhoid banding, infusions of biologics for inflammatory bowel disease, and office visits, with modifiers PT, 33, 59 and XS where they apply.
How We Keep GI Claims Clean
From scheduling to payment
We check coverage and screening eligibility before procedures, code from the procedure and pathology reports, and scrub claims for bundling edits between endoscopy codes. Denials go to our denial management team, and new gastroenterologists are enrolled through our credentialing services. See also our guide to modifier 59.
Payer Rules GI Practices Should Watch
Screening rules keep changing
Medicare covers screening colonoscopy for adults 45 and older and treats a colonoscopy after a positive stool-based test as part of screening. When a polyp is removed during a Medicare screening, coinsurance applies but is being phased down to zero by 2030. Commercial plans follow their own policies. We keep track so patients and payers are billed correctly.
Why GI Practices Choose Billing Care Assistant
Coders who know endoscopy
You get coders who understand screening versus diagnostic rules, close follow-up on every open claim, and monthly reports by provider, procedure and payer. Want to see where your practice is losing revenue? Start with a free medical billing audit, or see all the specialties we bill for.
Gastroenterology Billing FAQs
What happens when a screening colonoscopy becomes diagnostic?
The procedure is coded with the therapeutic code, such as polyp removal by snare, plus modifier PT for Medicare or modifier 33 for many commercial plans. This tells the payer the procedure started as a screening, so screening benefits can apply.
Which codes does Medicare use for screening colonoscopy?
G0121 for patients at average risk and G0105 for patients at high risk. Each has its own frequency limits.
Is a colonoscopy after a positive stool test considered screening?
For Medicare, yes, since 2023. Many commercial plans follow the same approach, but policies vary, so we check each payer.
Do you bill anesthesia for endoscopy?
We can bill anesthesia services for your providers or coordinate with your anesthesia group so procedure and anesthesia claims line up.
Not Sure Where Your Revenue Is Leaking?
Get a free, no-obligation medical billing audit. We review your claims, denials and A/R, then show you what to fix first.
