Does Medicare Cover Colonoscopy Screening? (2026)

Direct Answer: What Medicare Pays for Colonoscopy in 2026

Yes. Medicare Part B covers preventive colonoscopy at zero cost every 10 years for average-risk adults 50 and older, and every 2 years for high-risk patients. If a polyp is removed during the visit, ACA Section 4104 waives the Part B deductible (because the encounter started as preventive), and CAA 2021 Section 122 sets coinsurance at 15% for 2026, falling to 10% in 2027-2029 and 0% in 2030.

How Original Medicare Covers Colonoscopy

Original Medicare Part B covers colonoscopy under its preventive services benefit. Medicare pays 100% of the Medicare-approved amount when the procedure is billed as a screening colonoscopy (CPT code 45378). No Part B deductible, no coinsurance, and no copay applies to the preventive screening itself. The frequency rule is every 120 months (10 years) for average-risk beneficiaries and every 24 months (2 years) for high-risk beneficiaries. The age minimum is 50 for average-risk patients and any age for high-risk patients with a documented medical indication.

The ordering physician must be enrolled in Medicare and certify that the colonoscopy is performed for screening purposes. The facility (ambulatory surgery center or hospital outpatient department) must also accept Medicare assignment. If either the provider or facility does not accept assignment, Medicare still pays its share, but you may owe the difference between the Medicare rate and the provider's actual charge (called excess charges), up to 15% above the Medicare-approved amount.

The Diagnostic Upgrade: What Actually Happens When a Polyp Is Removed

When you schedule a routine preventive colonoscopy, the facility bills CPT 45378 (the screening colonoscopy code). If the gastroenterologist finds and removes a polyp during the same appointment, the billing code changes to CPT 45380 (colonoscopy with biopsy) or CPT 45385 (colonoscopy with polypectomy). CPT 45378 is the screening code. CPT 45380 and CPT 45385 are the therapeutic codes. Medicare classifies those therapeutic codes as diagnostic rather than preventive, which is what triggers the cost-share.

Two federal statutes change what that cost-share actually looks like in 2026. First, ACA Section 4104 (enacted 2010, implemented by CMS in 2011) waives the Part B deductible when a preventive colonoscopy converts to a therapeutic procedure during the same encounter. In 2026, that deductible is $283. Because the deductible is waived, you owe $0 toward the deductible regardless of whether it has been met for the year. Second, CAA 2021 Section 122 introduced a phase-down of the coinsurance rate that previously stood at 20%. For 2023 through 2026, coinsurance is 15%. For 2027 through 2029, it drops to 10%. Starting January 1, 2030, coinsurance on a diagnostic upgrade colonoscopy is 0%, making the procedure fully free even when a polyp is removed.

For a typical outpatient colonoscopy with polypectomy, the Medicare-approved amount runs $800 to $1,400 depending on facility type. At 15% coinsurance, your out-of-pocket in 2026 is $120 to $210, with no deductible owed. That is meaningfully lower than the pre-CAA exposure of 20% coinsurance plus the $283 deductible. Many beneficiaries still receive unexpected bills because the CAA 2021 phase-down is not yet widely understood by billing departments or patients.

What Medicare Advantage May Add in 2026

Medicare Advantage plans (Part C) must cover all Original Medicare preventive services, including the colonoscopy screening benefit. Many Medicare Advantage plans go further and waive the diagnostic upgrade cost-sharing entirely, meaning you pay $0 for colonoscopy even when a polyp is removed. According to KFF analysis, roughly half of Medicare Advantage plans nationally offered enhanced colorectal cancer screening benefits in 2025, with the trend continuing into 2026. Check your plan's Evidence of Coverage (EOC) document at the plan's website or at medicare.gov/plan-compare, and look at both the preventive colonoscopy and therapeutic colonoscopy benefit descriptions.

Medicare Advantage plans also vary on prior authorization requirements for colonoscopy. Original Medicare does not require prior authorization for preventive colonoscopy. Some Medicare Advantage plans do require prior authorization, particularly for high-risk patients who qualify for the 2-year frequency. Confirm your plan's prior authorization requirements before scheduling. If you are currently enrolled in a Medicare Advantage plan, call the member services number on your insurance card before booking.

High-Risk vs. Average-Risk: Frequency and Eligibility Criteria

Medicare defines high risk for colorectal cancer as meeting at least one of the following criteria: a close family member (parent, sibling, or child) diagnosed with colorectal cancer or adenomatous polyp before age 60; two or more close family members diagnosed at any age; personal history of adenomatous polyps; personal history of colorectal cancer; or chronic inflammatory bowel disease (Crohn's disease or ulcerative colitis). Beneficiaries meeting the high-risk definition qualify for colonoscopy every 2 years (24 months) rather than every 10 years.

For average-risk beneficiaries, the benefit begins at age 50. There is no upper age cutoff in the Medicare statute, though physicians should consider individual health status and life expectancy for patients over 85 in line with U.S. Preventive Services Task Force (USPSTF) guidance. The USPSTF recommends routine screening for all adults age 45 to 75; Medicare Part B aligns with this for enrolled beneficiaries.

Cost Without Medicare Coverage in 2026

For beneficiaries who pay full cost (self-pay), the 2026 price range for colonoscopy varies significantly by geography and facility type. FAIR Health data shows average facility charges of $1,500 to $4,500 for a colonoscopy with polyp removal at an ambulatory surgery center, and $2,500 to $6,000 at a hospital outpatient department. Physician fees (the gastroenterologist's professional fee, billed separately) typically add $300 to $700. These figures are the sticker prices before any negotiated rate. Providers who accept Medicare assignment agree to accept the Medicare-approved amount as payment in full, which is far below the sticker price.

If a colonoscopy complication requires a hospital admission, Medicare Part A (hospital insurance) covers the inpatient stay subject to the 2026 Part A deductible of $1,736. Bowel prep medications are typically covered under Medicare Part D if prescribed and dispensed before the procedure. Medigap Plan G covers the 15% coinsurance that applies when a polyp is removed in 2026, meaning Plan G enrollees pay $0 for colonoscopy regardless of the diagnostic upgrade.

Alternatives to Colonoscopy: What Medicare Also Covers for Colorectal Screening

Original Medicare covers several colorectal cancer screening alternatives for beneficiaries who cannot or choose not to have a colonoscopy. Fecal Occult Blood Test (FOBT) is covered annually at no cost. Multi-target stool DNA test (Cologuard) is covered every 3 years for average-risk adults age 45 to 85 with a physician order. Flexible sigmoidoscopy is covered every 4 years (or every 2 years if combined with FOBT) for patients without high-risk criteria. CT colonography (virtual colonoscopy) is not covered by Original Medicare as of 2026 but may be covered by some Medicare Advantage plans.

These alternative screening tests do not carry the diagnostic upgrade cost issue since they do not involve real-time polyp removal. If they detect an abnormality, a follow-up diagnostic colonoscopy is typically ordered. That follow-up colonoscopy is billed as diagnostic from the start (not preventive), so the deductible waiver and reduced coinsurance from ACA Section 4104 and CAA 2021 Section 122 do not apply to a separately ordered diagnostic colonoscopy. The CAA phase-down only applies when a single encounter starts as preventive screening and upgrades during the same procedure.

How to Schedule a Colonoscopy Under Medicare in 2026

Medicare covers preventive colonoscopy year-round with no enrollment window. The steps below apply to Original Medicare Part B beneficiaries. Medicare Advantage beneficiaries should complete steps 1 and 2, then confirm with their specific plan before booking.

• Step 1: Talk to your primary care physician or gastroenterologist. Get a written referral or order confirming the procedure is a preventive colonoscopy screening and note your risk category (average or high risk).
• Step 2: Verify the provider and facility accept Medicare assignment. Search at medicare.gov/care-compare. Non-participating providers can charge excess charges above the Medicare-approved rate.
• Step 3: If enrolled in Medicare Advantage, call the member services number on your insurance card and confirm prior authorization requirements and whether the plan waives the polyp-removal upgrade cost-share.
• Step 4: At scheduling, confirm with the facility billing department that the claim will be submitted under CPT 45378 (the screening colonoscopy code) and ask what your cost-share would be if a polyp is found and removed. Remind them that ACA Section 4104 waives the deductible and CAA 2021 sets 15% coinsurance for 2026.
• Step 5: After the procedure, review your Medicare Summary Notice (MSN) or Explanation of Benefits (EOB). If you see a deductible charge on a colonoscopy that started as preventive screening, dispute it by calling 1-800-MEDICARE (1-800-633-4227) or contacting your State Health Insurance Assistance Program (SHIP) for free counseling.

Does Original Medicare cover colonoscopy at no cost?

Yes, for a purely preventive colonoscopy (CPT 45378) with no polyp removal. Original Medicare Part B pays 100% with no deductible and no coinsurance. If the doctor finds and removes a polyp, the billing code upgrades to CPT 45380 or CPT 45385. Per ACA Section 4104, the Part B deductible ($283 in 2026) is waived. Per CAA 2021 Section 122, coinsurance is 15% in 2026 (not the standard 20%), dropping to 10% in 2027-2029 and 0% in 2030.

What is the colonoscopy diagnostic upgrade and how much does it cost in 2026?

The diagnostic upgrade happens when a polyp is removed during a preventive colonoscopy, changing the CPT code from 45378 (the screening code) to CPT 45380 or CPT 45385 (therapeutic codes). Under Original Medicare in 2026, ACA Section 4104 waives the Part B deductible entirely because the encounter started as a preventive screening. CAA 2021 Section 122 sets coinsurance at 15% for 2026. For a typical outpatient colonoscopy, 15% of the Medicare-approved amount is approximately $120 to $210, with no deductible owed.

Does Medicare Advantage cover colonoscopy differently?

Many Medicare Advantage plans go beyond Original Medicare and waive the polyp-removal upgrade cost-share entirely, meaning you pay $0 even if a polyp is found. Roughly half of Medicare Advantage plans nationally offered this enhanced benefit in 2025. Check your Evidence of Coverage document or call member services before scheduling. Some Medicare Advantage plans also require prior authorization, which Original Medicare does not require.

Does Medigap cover the colonoscopy cost-share when a polyp is removed?

Yes. Medigap Plan G covers the 15% Part B coinsurance that applies when a polyp is removed in 2026 (the diagnostic upgrade coinsurance per CAA 2021 Section 122). The Part B deductible is already waived by ACA Section 4104, so Plan G enrollees pay $0 total for colonoscopy even with a polyp removal. Plan F also covers both deductible and coinsurance but is only available to beneficiaries who became eligible before January 1, 2020.

How often does Medicare cover colonoscopy?

Every 120 months (10 years) for average-risk beneficiaries age 50 and older. Every 24 months (2 years) for high-risk patients (prior polyps, family history of colorectal cancer before age 60, inflammatory bowel disease, personal history of colorectal cancer). If your prior colonoscopy found and removed a polyp, ask your gastroenterologist to document high-risk status so you qualify for the shorter 2-year frequency.

What CPT codes does Medicare use for colonoscopy?

CPT 45378 is the screening colonoscopy code, billed when the procedure starts as a preventive screening. CPT 45380 is colonoscopy with biopsy. CPT 45385 is colonoscopy with polypectomy. CPT 45380 and CPT 45385 are the therapeutic or diagnostic codes. When a polyp is removed, the GI center bills CPT 45380 or CPT 45385, triggering the diagnostic upgrade. ACA Section 4104 waives the deductible when 45378 started the encounter. CAA 2021 sets 15% coinsurance for 2026.

Are there alternatives to colonoscopy that Medicare covers?

Yes. Medicare Part B covers fecal occult blood test (FOBT) annually, multi-target stool DNA test (Cologuard) every 3 years for average-risk adults age 45 to 85, and flexible sigmoidoscopy every 4 years. CT colonography (virtual colonoscopy) is not covered by Original Medicare as of 2026 but may be covered by some Medicare Advantage plans. These alternatives do not carry the polyp-removal diagnostic upgrade issue since they do not involve real-time polyp removal.

What happens if Medicare denies my colonoscopy claim?

You have five levels of appeal. Start with a Redetermination request to your Medicare Administrative Contractor (MAC) within 120 days of the denial on your Medicare Summary Notice (MSN). If denied again, request a Reconsideration from the Qualified Independent Contractor (QIC). Further appeals go to an Administrative Law Judge (ALJ), the Medicare Appeals Council, and ultimately federal court. Contact your State Health Insurance Assistance Program (SHIP) for free help at medicare.gov/talk-to-someone.