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Gastroenterology billing services · Endoscopy · Anesthesia
PhysiAssist runs GI billing and revenue cycle management for gastroenterology practices, endoscopy centers and the anesthesia teams beside them. We code every colonoscopy the way each payer wants it, keep screening benefits intact when a polyp comes out, and keep office visits, infusions and pathology paid.
Screening colonoscopy checker
Try itProcedure
Anesthesia
Patient owes
Medicare 2026 rules and ACA preventive rules; plans vary
The basics
Gastroenterology billing services manage the revenue cycle of a GI practice: coding of office visits and procedures, colonoscopy and EGD, screening versus diagnostic rules, anesthesia for endoscopy, endoscopy center and ASC facility claims, IBD infusions and pathology, claim submission, payment posting, denials and AR. In GI most lost revenue starts with a screening colonoscopy coded the wrong way.
E/M, colonoscopy, EGD, biopsies, polypectomy, dilation and capsule endoscopy.
Facility claims and professional fees for the same case, checked against the contract.
MAC and CRNA billing with 00811, 00812 and 00813 and the right provider modifiers.
Infliximab, vedolizumab and ustekinumab by the unit, and in-house pathology.
What we check
| Codes | What they cover | What we check |
|---|---|---|
| G0121 · G0105 | Medicare screening colonoscopy, average and high risk | Frequency (10 years or 24 months), and that nothing turned the scope diagnostic |
| 45378 · 45380 · 45385 | Diagnostic colonoscopy, biopsy, snare polypectomy | Technique documented, and PT or 33 when the scope started as screening |
| Modifier KX | Colonoscopy after a positive stool-based test | The positive FIT or stool DNA result on file so Medicare treats it as screening |
| 43235 · 43239 · 43249 | EGD, with biopsy, with balloon dilation | Each technique and the diagnosis that supports it |
| 00811 · 00812 · 00813 | Anesthesia for lower, screening and combined endoscopy | Code matches the procedure claim, with QS, AA, QK, QX or QZ as documented |
| J1745 · J3380 · J3358 | Infliximab, vedolizumab, ustekinumab IV | Units, waste lines, authorization and administration codes |
| 88305 | Surgical pathology, per specimen | Specimen count matches the separately identified samples |
Free colonoscopy billing audit
Send us a recent month of colonoscopy, endoscopy and anesthesia claims. A certified coder checks every one and sends a written report you keep, whether or not you work with us.
Claims reviewed
240With an issue
19Dollar impact
$9,800What the report covers
Where GI meets the surgery center
Most GI revenue moves between three claims for one patient. We bill all three, so a screening that turns diagnostic is coded the same way on each.
The systems we work in every day
We log in to your system; nothing about it changes for your team.
Claims, rejections and remittances worked through your clearinghouse.
Submissions, status checks and renewals in each payer's own portal.
Pricing
One rate of 2.8% to 5% of net collections, quoted in writing before you sign. Where you land depends on monthly collections, specialty mix, the scope of services, and your AR backlog and payer mix.
The rate covers medical coding, claim submission, payment posting, denials and AR follow-up. Front desk services, prior authorization, the reporting dashboard, patient statements, credentialing and digital marketing are quoted separately.
See full pricing and estimate your rate →Eligibility and prior authorization, coding of office visits, colonoscopy, EGD, biopsies and polypectomy, anesthesia for endoscopy, ASC and endoscopy center facility claims, IBD infusions, in-house pathology, claim submission, payment posting, denials, AR follow-up and patient billing.
For Medicare, bill the diagnostic code (for example 45385 for snare polypectomy) with modifier PT so the screening benefit still applies; the deductible is waived and the patient owes 15% coinsurance in 2026. For commercial plans, add modifier 33; under ACA preventive rules polyp removal during screening carries no cost share for non-grandfathered plans.
Medicare uses KX on a screening colonoscopy that follows a positive non-invasive stool-based test, such as a FIT or multi-target stool DNA test, to show the colonoscopy completes the screening.
Screening colonoscopy anesthesia is 00812 and diagnostic or converted cases use 00811, with 00813 for combined upper and lower endoscopy. Provider modifiers (AA, QK, QX, QZ) and QS for monitored anesthesia care must match the record, and PT or 33 follows the procedure claim.
Yes. We bill the facility claim for the endoscopy center or ASC and the gastroenterologist's professional claim, and check both against each payer's contract. See our ASC billing services.
Yes. Biologic infusions such as infliximab and vedolizumab are billed by the drug unit with the administration codes, waste lines and authorization, and in-house pathology such as 88305 is billed with the right specimen count.
PhysiAssist charges 2.8% to 5% of net collections for coding, claims, payment posting, denials and AR, quoted in writing before you sign.
We review recent colonoscopy, endoscopy and anesthesia claims and send a written report: screening versus diagnostic coding, PT, 33 and KX modifiers, anesthesia matches, pathology, denials by root cause and the dollar value of each.
A free colonoscopy billing audit by a certified coder, with a written report you keep.