Does Medicare Cover a Colonoscopy?

What Medicare covers and what you pay

A screening colonoscopy is a preventive test you get when you have no symptoms. Medicare Part B covers it, and if your doctor accepts assignment (agrees to Medicare's approved amount) and no polyp or tissue is removed, you pay $0 — no coinsurance and no Part B deductible.

There is no minimum age requirement for a screening colonoscopy under Medicare. Medicare covers the screening regardless of your age, which is different from some other colorectal tests that only cover certain age ranges.

Medicare covers the colonoscopy under Part B (medical insurance), not Part A. Part A would only come into play if you were formally admitted to a hospital as an inpatient, which is not how a routine colonoscopy is handled.

How often Medicare pays for a screening colonoscopy

How often Medicare will cover your screening depends on your risk level for colorectal cancer.

• If you are at high risk: once every 24 months (every 2 years).
• If you are not at high risk: once every 120 months (every 10 years), or 48 months after a previous screening flexible sigmoidoscopy.
• High risk generally means you have a personal or family history that raises your chances of colorectal cancer. Your doctor determines and documents whether you meet Medicare's high-risk criteria, so ask your provider how you are coded before the test.

Why you might get a bill: the polyp rule

This is the most common reason people are surprised by a charge after a 'free' colonoscopy. If the doctor finds and removes a polyp or other tissue during your screening, the procedure is reclassified as diagnostic or therapeutic, and Medicare's cost-sharing kicks in.

For dates of service in 2023 through 2026, you pay 15% coinsurance of the Medicare-approved amount for the doctor's services. If the colonoscopy is done in a hospital outpatient department or an ambulatory surgical center, you also pay a 15% facility coinsurance. Importantly, the Part B deductible ($283 in 2026) does NOT apply, even when a polyp is removed.

This reduced coinsurance is being phased out under a federal schedule. The beneficiary coinsurance for a screening colonoscopy that becomes diagnostic is 15% for 2023-2026, drops to 10% for 2027-2029, and reaches 0% starting in 2030.

Screening vs. diagnostic: a big cost difference

The phase-down (15% / 10% / 0%) only applies when a planned colorectal cancer SCREENING test becomes diagnostic in the same visit — for example, a polyp is removed during your routine screening.

A colonoscopy that is ordered as diagnostic from the start — because you have symptoms such as blood in your stool, abdominal pain, or a change in bowel habits — is treated differently. It is subject to the standard 20% Part B coinsurance AND the Part B deductible ($283 in 2026). It is not a free preventive screening.

Medicare also covers a follow-up colonoscopy when a non-colonoscopy colorectal screening (such as a stool test or a blood-based test) comes back positive. In that case, the colonoscopy is covered as a screening, so it falls under the same screening rules and phase-down coinsurance rather than full diagnostic cost-sharing.

Other colorectal screenings and Medicare Advantage

A colonoscopy is not the only colorectal screening Medicare covers. Medicare also covers a blood-based biomarker colorectal cancer screening test once every 3 years for people ages 45-85 who are at average risk and have no symptoms.

• If you have a Medicare Advantage (Part C) plan, it must cover everything Original Medicare covers, including screening colonoscopies. However, in-network requirements and the cost-sharing for the polyp-removal portion can differ by plan.
• Always confirm details — including whether your doctor and facility are in-network and how anesthesia is billed — with your specific plan before the procedure. Check your plan's Evidence of Coverage; benefits vary by plan.
• MedicareLoginGuide.com is an independent resource and is not affiliated with the federal Medicare program or any government agency.