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Gastroenterology Billing Services

Gastroenterology billing is shaped by one moment: the point during a screening colonoscopy when a polyp is found and removed. From then on the procedure is coded as therapeutic, the screening intent must still be shown on the claim, and the anesthesia provider, the facility and the pathologist all need to describe the same procedure the same way.

  • Screening intent preserved with PT or 33 when a colonoscopy becomes therapeutic
  • Polyp removal coded by technique, not by number of polyps
  • Endoscopist, anesthesia, facility and pathology claims kept consistent
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When a screening colonoscopy turns diagnostic

For Medicare, a planned screening colonoscopy on an average-risk patient is billed with a screening HCPCS code. If a polyp is removed, the procedure is instead reported with the CPT code for the therapeutic service and modifier PT, and the screening diagnosis stays first on the claim, so the patient's deductible still does not apply. Other payers may expect modifier 33 instead, so we follow each plan's rule.

What the patient owes in that case is set by law and is being phased down over several years, so it changes on a published schedule. We apply the percentage in effect on the date of service and track the current figure rather than quoting one here, because a wrong statement to a patient becomes a billing dispute.

The rest of the day has its own rules. Polyp removal codes are chosen by technique, such as cold snare or hot biopsy forceps, and each technique is reported once per session however many polyps it removed. Moderate sedation by the endoscopist is billed separately from the endoscopy, while an anesthesia professional bills with the anesthesia codes for lower GI endoscopy.

Official sources: eCFR: 42 CFR 410.152 (Part B payment for colorectal cancer screening) (external site), eCFR: 42 CFR 410.37 (colorectal cancer screening tests) (external site)

Endoscopy, polyp removal and sedation codes

Codes and modifiers for a typical GI procedure day. Confirm with current CPT, HCPCS and payer policy.

Gastroenterology codes and modifiers with billing notes
Codes or modifiersServiceBilling notes
G0121, G0105Medicare screening colonoscopy for a patient not at high risk, and at high risk.Used only when the procedure stays a screening service.
45378Diagnostic colonoscopy.The base code for colonoscopy; therapeutic codes replace it when biopsy or removal is performed.
45380, 45384, 45385, 45388Colonoscopy with biopsy, removal by hot biopsy forceps, removal by snare, and ablation.One unit per technique per session, however many polyps it removed. Combinations of techniques are checked against the NCCI edit for that code pair.
PT and 33Screening that became diagnostic or therapeutic: Medicare uses PT; other payers may use 33.Keeps the screening intent visible so preventive benefits apply.
43235, 43239Diagnostic upper GI endoscopy (EGD), and EGD with biopsy.Biopsy code covers one or more biopsies in the session.
G0500, 99152, 99153Moderate sedation by the endoscopist: for Medicare GI endoscopy, G0500 for the first 15 minutes; other payers may use 99152; 99153 for additional time.Separately reportable by the physician performing the procedure. The sedation and anesthesia claims for the case are checked against each other.
00811, 00812Anesthesia for lower GI endoscopy, and for screening colonoscopy.Billed by the anesthesia provider; when a screening colonoscopy turns diagnostic, Medicare expects 00811 with PT.

CPT is a registered trademark of the American Medical Association.

Official sources: CMS Claims Processing Manual, chapter 18 (preventive services) (external site), CMS NCCI Policy Manual, chapter 6 (digestive system) (external site), CMS Medicare Coverage Database: article A55937 (colonoscopy codes) (external site), CMS: HCPCS quarterly file (external site), eCFR: 42 CFR 414.22 (facility and non-facility practice expense) (external site), CMS coverage database: article A55227 (external site), CMS coverage database: article A56389 (external site)

GI claim errors that cost patients and practices

  • Screening intent lost

    A converted colonoscopy billed without PT or 33, or with the screening diagnosis moved down, so the patient is charged a deductible.

  • One code per polyp

    The same removal technique billed several times for several polyps instead of once.

  • Anesthesia claim does not match

    The anesthesia provider bills a diagnostic code while the endoscopist bills screening, or the reverse.

  • Sedation billed twice

    Endoscopist moderate sedation codes billed when an anesthesia professional also billed for the case.

  • High-risk screening without the history

    G0105 used without documentation of the personal or family history that makes the patient high risk.

How we bill endoscopy days

  1. Step 1: Record the intent before the scope

    Each case is flagged at scheduling as screening, surveillance or diagnostic, so the claim reflects why it was planned.

  2. Step 2: Code from the procedure report

    Techniques, sites and findings are coded from the report, with screening modifiers applied when the procedure converted.

  3. Step 3: Align the anesthesia claim

    The anesthesia code, modifiers and diagnosis are matched to the endoscopist's claim for the same case.

  4. Step 4: Close the pathology loop

    Pathology results are linked back to the case so follow-up and surveillance intervals are coded correctly.

ASC, hospital outpatient and office endoscopy

Where the procedure happens changes who bills what.

Endoscopy billing by site of service
SettingFacility claimEndoscopist claim
Ambulatory surgery centerThe ASC bills its facility fee for the procedure.Professional claim at the facility rate, with the ASC place of service.
Hospital outpatientThe hospital bills the facility side on its institutional claim.Professional claim at the facility rate, with the hospital outpatient place of service.
Office endoscopy suiteNo separate facility claim.Professional claim at the non-facility rate, which includes practice expense.

Frequently asked questions

Does a patient pay anything if a polyp is removed during a screening colonoscopy?

For Medicare, the deductible does not apply, but a coinsurance may, at a percentage set by law that is being reduced over several years. We bill with modifier PT so the reduced amount applies and track the current percentage.

Official source: eCFR: 42 CFR 410.152 (Part B payment for colorectal cancer screening) (external site)

Is a colonoscopy after a positive stool test screening or diagnostic?

Medicare treats a follow-on colonoscopy after a positive stool-based screening test as part of screening. Other plans set their own rule, which affects modifiers and patient cost share, so we check the plan before the procedure.

How do we code three polyps removed by cold snare?

Report the snare removal code once for the session. If another polyp was removed by a different technique, we check the NCCI edit for that pair before adding its code.

Who bills the sedation for a colonoscopy?

If the endoscopist provides moderate sedation, it is billed with the sedation codes, G0500 for Medicare GI endoscopy. If an anesthesiologist or CRNA provides anesthesia, they bill the anesthesia code, and we check that the endoscopist's claim does not also carry sedation for the same case.

Do we bill the pathology?

Usually not. The pathologist or lab that examines the specimen bills for it, unless your practice has its own pathology lab and pathologist.

Related services and specialties

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