CMS has spent the past three years systematically expanding colorectal cancer screening coverage — adding new modalities, eliminating patient cost-sharing and lowering the eligible age.
For high-volume GI ASCs, the policy changes carry a reimbursement paradox: more patients are coming in, and the payment per procedure is going down.
What changed and when
The policy evolution has unfolded across multiple CMS final rules. The foundational shift came in 2023. CMS expanded Medicaid coverage for colorectal cancer screening by reducing the minimum age for certain screening tests from 50 to 45, and expanded the regulatory definition of screening tests to include a complete colorectal cancer screening, where a follow-up colonoscopy after a Medicaid-covered noninvasive stool-based test comes back positive, with cost sharing not applying for most beneficiaries for either the initial test or the follow-on colonoscopy.
The CY 2025 Physician Fee Schedule built further on that foundation, adding coverage for CT colonography and blood-based biomarker screening tests to the continuum, meaning a positive blood-based result now triggers a follow-on colonoscopy with no patient cost-sharing, according to the American College of Gastroenterology. The utilization effect is already documented: removing cost-sharing for follow-up colonoscopy significantly increased procedure rates nationwide, according to a study published in Current Medical Research and Opinion in October 2025.
The reimbursement cut arriving with the volume
More colonoscopies are being performed, and the payment per procedure is falling. Two CMS policy changes, a 2.5% efficiency adjustment to work RVUs for non-time-based services and a revision to the practice expense methodology, will cut payments to gastroenterologists for ASC and hospital-based endoscopy by $58 million, while boosting payments for office-based endoscopy by more than $37 million, according to the AGA. At the procedure level, ASCs and hospital outpatient departments face an average 8% physician payment cut, while office-based endoscopy sees a 16% increase.
The per-procedure impact is concrete: a colonoscopy with biopsy (CPT 45380) pays $14.65 less than in 2025; a colonoscopy with snare polypectomy (CPT 45385) pays $18 less, according to the ACG.
The PT modifier and coding implications
When a screening colonoscopy converts to a diagnostic or therapeutic service during the encounter, the PT modifier must be appended to at least one code on the claim. For dates of service through Dec. 31, 2026, a deductible and reduced 15% coinsurance apply. That coinsurance phases down to zero by Jan. 1, 2030. ASCs need revenue cycle systems updated to reflect the correct coinsurance year by year, and accurate screening vs. diagnostic coding, since PT modifier status determines what the patient owes and what the facility collects.
The office-based migration risk
The CMS rate structure is now explicitly incentivizing GI procedures to migrate out of ASCs. In Illinois, Oregon, Virginia, Washington and Wisconsin, health plans are already introducing programs to transition outpatient endoscopy to office-based settings, according to the AGA. A practice performing 900 colonoscopies per year using CPT 45378 could see a $45,891 Medicare payment increase by shifting to an office setting, a calculation that is not lost on the gastroenterologists whose cases fill ASC schedules.
The bottom line
The convergence of three forces, a 40-year decline in colonoscopy reimbursement, a 2026 fee schedule that rewards office-based endoscopy over ASC-based endoscopy and a cost-sharing policy driving more patients into the pipeline without a corresponding payment increase, means volume growth alone will not solve the margin problem. The ASC conversion factor is $56.322 in 2026, compared with $91.415 for hospital outpatient departments. The centers that hold will be those that negotiate commercial rates above the Medicare floor and can make a credible quality argument to payers — adenoma detection rates at or above 35% and at least 90% adherence to surveillance intervals, per national GI society benchmarks — to justify keeping high-volume GI work in the surgery center.
At the Becker’s 32nd Annual Meeting: The Business and Operations of ASCs, taking place October 29-31 in Chicago, ASC leaders, surgeons and healthcare executives will explore strategies to drive growth, enhance operational performance, navigate reimbursement challenges and prepare for the future of ambulatory surgery. Apply for complimentary registration now.