Medicare covers most of the cost of a colonoscopy, but you will pay something out of pocket — the amount depends on whether your doctor finds anything that needs treatment and which Medicare plan you have.
If your colonoscopy is screening only (no polyps removed, no biopsies taken), Medicare Part B covers the full cost and you pay nothing. If your doctor removes polyps or takes tissue samples during the same visit, the procedure shifts to a diagnostic colonoscopy, and you become responsible for your coinsurance — typically 20 percent of the Medicare-approved amount after you have met your Part B deductible.
The Medicare-approved amount varies by region and facility. A screening colonoscopy might be approved at $500 to $800; a diagnostic one at $800 to $1,200 or more. Your actual bill depends on what your specific facility charges and what Medicare allows in your area. If you have a Medigap or Medicare Advantage plan, your out-of-pocket cost may be lower or zero.
Key Takeaways
- Screening colonoscopies (no treatment during the procedure) are fully covered by Medicare Part B with no cost to you.
- If polyps are removed or biopsies taken, you pay 20 percent coinsurance after meeting your Part B deductible, which varies by region.
- Your facility's location and the specific procedure code used determine the Medicare-approved amount and your final bill.
- Medigap Plan C or F, or a Medicare Advantage plan with low or zero coinsurance, can reduce or eliminate your out-of-pocket cost.
- Ask your gastroenterologist's office before the procedure whether they expect to do screening only or whether polyp removal is likely.
When Medicare Covers the Full Cost
Medicare Part B covers a screening colonoscopy at 100 percent if the procedure is truly preventive — meaning your doctor looks for polyps and cancer but does not remove anything or take biopsies. You must have no symptoms and no personal or family history that would make this a diagnostic procedure instead. You pay zero dollars.
Medicare covers screening colonoscopies once every 10 years for people age 50 and older (or every 5 years if you have had a normal colonoscopy before). If you are under 50 but have symptoms or risk factors, Medicare may cover a diagnostic colonoscopy instead, which has a different cost structure.
When You Pay Coinsurance
The moment your doctor removes a polyp, takes a biopsy, or treats anything during the colonoscopy, Medicare reclassifies the procedure as diagnostic. You then owe 20 percent coinsurance on the Medicare-approved amount, after you have met your Part B deductible for the year.
The Part B deductible is $240 in 2024, though this amount changes yearly. If you have already met your deductible earlier in the year (for example, through an office visit or lab work), you pay only the 20 percent coinsurance. If you have not met it, you pay the full deductible first, then 20 percent of the remaining approved amount.
Example: If the Medicare-approved amount for a diagnostic colonoscopy with polyp removal is $1,000 and you have not met your deductible, you pay $240 (deductible) plus $152 (20 percent of the remaining $760), for a total of $392. If you had already met your deductible, you would pay only $200 (20 percent of $1,000).
How Your Facility and Region Affect the Cost
Medicare sets an approved amount for each procedure code based on the geographic area where you receive care. A colonoscopy performed at a hospital outpatient department typically has a higher approved amount than the same procedure at an ambulatory surgery center or office-based endoscopy suite. Your region's cost of living and local provider density also affect the approved amount.
You can look up the Medicare-approved amount for your area before your procedure. Visit the Medicare Physician Fee Schedule Look-Up tool on the Centers for Medicare & Medicaid Services (CMS) website. Search for procedure code 45398 (screening colonoscopy) or 45398 with modifier (diagnostic with polyp removal). Enter your state and facility type to see the approved amount in your region.
How Medigap and Medicare Advantage Plans Change Your Cost
If you have a Medigap plan (supplemental insurance), the plan type determines how much of your coinsurance it covers. Medigap Plan C and Plan F cover the Part B coinsurance in full, so you pay nothing out of pocket for a diagnostic colonoscopy. Other Medigap plans cover part of the coinsurance or none of it. Check your plan documents or call your Medigap insurer to confirm what your plan covers.
If you have a Medicare Advantage plan (Part C), your out-of-pocket cost depends on your plan's copay or coinsurance structure. Some plans charge a flat copay ($0 to $500) for an outpatient procedure; others charge a percentage coinsurance. Many Medicare Advantage plans cover preventive colonoscopies at no cost. Call your plan before scheduling to confirm whether your colonoscopy will be covered as preventive or diagnostic and what you will owe.
What to Ask Your Doctor Before the Procedure
Contact your gastroenterologist's office at least one week before your appointment and ask: "Do you expect this to be a screening colonoscopy only, or are you likely to remove polyps or take biopsies?" This question matters because the answer tells you whether to expect a zero bill or a coinsurance bill.
If your doctor has reason to suspect polyps or abnormalities based on your symptoms or prior imaging, the procedure will likely be diagnostic from the start. If you are coming in for routine screening with no symptoms, it should be screening only — unless your doctor finds something unexpected during the exam.
Also ask whether your facility is in-network with your Medicare Advantage plan (if you have one) and whether they can estimate your out-of-pocket cost based on your plan. Some offices have billing staff who can pull this information while you are on the phone.
What Happens If You Receive a Surprise Bill
If you receive a bill that seems higher than expected, review it carefully. Check that the procedure code matches what was actually done — a screening code should not appear if polyps were removed. If the code is wrong, contact your doctor's billing office and ask them to correct it and resubmit to Medicare.
If the code is correct but the bill is from an out-of-network facility (even though you thought it was in-network), you may have additional protections under the No Surprises Act. This federal rule limits your out-of-pocket cost for emergency or certain non-emergency services at out-of-network facilities. Contact your Medicare Advantage plan or the facility's billing office to dispute the charge.
Frequently Asked Questions
Do I have to pay anything if my colonoscopy is screening only?
No. Medicare Part B covers the full cost of a screening colonoscopy with no symptoms or findings. You pay nothing, even if you have not met your Part B deductible. The procedure must be coded as screening (not diagnostic) for this to explore.
What if my doctor finds a polyp but decides not to remove it?
If your doctor identifies a polyp but does not remove it during the same visit, the procedure is still coded as diagnostic, and you owe coinsurance. Removal and biopsy are what trigger the diagnostic code; identification alone does not. Ask your doctor before the procedure whether they plan to remove any polyps they find.
Will my Medicare Advantage plan cover a colonoscopy the same way as Original Medicare?
No. Medicare Advantage plans set their own copays and coinsurance amounts, which vary by plan. Many cover preventive colonoscopies at no cost, but diagnostic ones may have a copay or coinsurance. Call your plan's member services line to confirm your out-of-pocket cost before scheduling.
Can I ask my doctor to do screening only even if I have symptoms?
No. If you have symptoms (bleeding, pain, changes in bowel habits) or a family history of colorectal cancer, Medicare requires the procedure to be coded as diagnostic, regardless of what you request. The coding is based on medical necessity, not patient preference.
How do I know if I have met my Part B deductible?
Check your Medicare Summary Notice (the statement Medicare sends you quarterly) or log into your Medicare account at Medicare.gov. Search for "deductible" to see how much you have paid toward your deductible so far this year. You can also call Medicare at 1-800-MEDICARE to ask.