Gastroenterology Billing Services

Gastroenterology billing turns on a distinction that changes the patient’s cost and the payer’s payment: screening versus diagnostic. The same colonoscopy is coded differently depending on why the patient came in, what was found, and whether the payer is Medicare or commercial, and the wrong path produces denials, duplicate-procedure edits, and surprise cost-sharing for the patient.
MedPlus RCM provides medical billing, coding, credentialing, and denial management for gastroenterology practices, built around endoscopy and screening program coding.

Gastroenterology billing challenges

The screening-to-diagnostic conversion is the central challenge. For Medicare, a screening colonoscopy with no intervention is reported with G0121 for average-risk patients or G0105 for high-risk patients. For commercial and marketplace plans, the same screening is generally reported with the diagnostic base code 45378 plus modifier 33 to signal a preventive service. When a screening exam finds a polyp or lesion that is treated, the claim converts to the therapeutic code matching what was done, such as 45380 for biopsy or 45385 for polypectomy, with modifier PT for Medicare or modifier 33 for commercial plans. Billing the screening code and the therapeutic code together for the same exam reads as two colonoscopies and denies as a duplicate.
Medical necessity documentation is the second challenge. Upper endoscopy claims frequently deny when the diagnosis on the claim is a vague symptom rather than the specific finding or established diagnosis the payer’s coverage policy requires. The note must document the presenting symptom with duration and severity, prior treatment failures, and relevant history such as prior ulcer or alarm features, so the coded diagnosis reflects what actually justified the exam.
Bundling and authorization complete the picture. Biopsy and polypectomy codes bundle against each other under payer edits, capsule endoscopy typically requires prior authorization, and stool-based test follow-up colonoscopies carry their own screening qualification rules. Each of these must be handled at claim build time, not at denial time.

What MedPlus RCM handles for gastroenterology practices

  • End-to-end medical billing. Charge entry, claim scrubbing, submission, payment posting, and patient billing, the full cycle.
  • Medical coding. Certified coders assign current ICD-10, CPT, and HCPCS codes matched to your documentation and specialty.
  • Provider credentialing and enrollment. End-to-end enrollment with commercial payers, Medicare, and Medicaid, plus re-credentialing maintenance.
  • Denial management and recovery. Every denial investigated to root cause, corrected, and appealed with documentation.
  • A/R recovery. Aged and outstanding balances audited and pursued, including balances already written off where the appeal window is still open.
  • Financial reporting. Clean claim rates, collections, denial patterns, and A/R aging visible by payer and provider.

We serve gastroenterology practices of every size, from solo physicians to multi-provider groups, across all 50 states.

Results gastroenterology practices can check

MedPlus RCM maintains a 99% clean claim rate and keeps client accounts receivable under 30 days. Pricing is a performance-based percentage of successfully collected revenue: if you don’t get paid, we don’t get paid. We are 100% HIPAA compliant, and onboarding takes 2 to 4 weeks depending on practice size, with no disruption to your daily cash flow.

Frequently asked questions

What is the difference between a screening and a diagnostic colonoscopy?
A screening colonoscopy is performed on a patient with no symptoms, purely to look for cancer or precancerous polyps. A diagnostic colonoscopy investigates a specific problem, such as bleeding, a change in bowel habits, or a positive stool test. The reason for the exam sets the coding path and the patient’s cost-sharing.
How is a screening colonoscopy coded for Medicare versus commercial plans?
For Medicare, a screening with no intervention uses G0121 for average-risk patients or G0105 for high-risk patients. For commercial plans, the screening is generally reported with 45378 plus modifier 33.
What happens when a polyp is found during a screening?
The claim converts to the therapeutic code matching what was done, such as 45385 for polypectomy, with modifier PT for Medicare or modifier 33 for commercial plans, preserving the screening history. The screening code and the therapeutic code must not be billed together for the same exam.
Why do upper endoscopy claims deny for medical necessity?
Usually because the diagnosis coded is a vague symptom rather than the specific finding or established diagnosis the payer requires. The note must document symptom duration and severity, prior treatment failures, and relevant history.
How long does it take to switch our billing to MedPlus RCM?
Onboarding takes between 2 and 4 weeks depending on practice size, including data migration and payer clearinghouse setup.
What does MedPlus RCM charge?
A performance-based percentage of successfully collected revenue. If you don’t get paid, we don’t get paid.

Get a free financial audit

Find out where your gastroenterology practice is losing revenue. Request a free financial audit and our specialists will review your claims, denials, and A/R.
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