A colonoscopy is one of the best tools for catching colorectal cancer early, and Medicare makes screening free. But a longstanding quirk, a surprise bill when a polyp is removed, has confused patients for years, and the good news is that it is being phased out. This guide explains what Medicare covers, how often, and how to avoid an unexpected charge. Coverage and costs change, so verify current details before relying on them.
The Short Answer
Yes. Medicare Part B covers screening colonoscopies as a preventive service at $0, with no deductible or coinsurance, when the provider accepts assignment. There is no minimum age. The main caveat involves polyp removal, which is covered but has historically carried some cost-sharing that is now shrinking toward zero.
How Often Medicare Covers a Screening
The frequency depends on your risk. If you are at high risk for colorectal cancer, Medicare covers a screening colonoscopy every 24 months. If you are not high risk, it is covered every 120 months, or ten years, or 48 months after a flexible sigmoidoscopy. Medicare also covers a follow-up colonoscopy at $0 as a screening if you first had a covered stool-based test, such as a fecal test or Cologuard, or a blood-based test that came back positive.
The Polyp Removal Rule
Here is the part that catches people out. If the doctor finds and removes a polyp during your screening, the procedure technically becomes therapeutic, and historically that triggered coinsurance. Under a federal law, that coinsurance is being phased out: it was 20%, dropped to about 15% for 2023 through 2026, falls to 10% for 2027 through 2029, and reaches 0% in 2030. The Part B deductible does not apply. So the old āsurprise billā is steadily disappearing, but check the current-year percentage.
Screening vs Diagnostic
There is an important distinction. A colonoscopy ordered because of symptoms, such as bleeding or pain, or to follow up on a known condition, is diagnostic, not screening. For a diagnostic colonoscopy you pay the standard 20% coinsurance and the Part B deductible applies. Because the same procedure can be billed either way, it is worth asking your provider how yours will be coded.
What You Will Pay
You pay $0 for a clean screening. If a polyp is removed, you currently pay about 15% of the approved amount, an amount that is phasing to zero by 2030. If the colonoscopy is diagnostic, you pay the standard 20% plus the deductible. A Medigap policy can cover the coinsurance, and Medicare Advantage plans cover screening at $0 in-network, so confirm your provider is in-network.
What to Do
Before the procedure, ask both the provider and the facility how it will be billed and confirm they accept assignment. If you are billed for what you believed was a free screening, check whether it was reclassified because a polyp was removed, and appeal any billing error.
Screening vs Diagnostic Colonoscopy
Here is a crucial distinction that affects your cost. A screening colonoscopy and a diagnostic one are billed differently.
A routine screening colonoscopy is covered with no cost to you. But if a polyp is found and removed during the screening, it can become diagnostic. That may add a cost share. Ask your doctor how the procedure will be billed so you are not caught off guard.
How Often Medicare Covers It
Coverage frequency depends on your risk. Medicare sets intervals for screening.
For people at average risk, Medicare covers a screening colonoscopy at set intervals. For those at higher risk, it may be covered more often. Your doctor determines your risk level. If it is time for a screening, it is a valuable, covered benefit.
Other Covered Screenings
A colonoscopy is not the only covered colorectal screening. Medicare covers several options.
These include certain stool-based tests and other screening methods. Each has its own schedule. Your doctor can help you choose the right screening for you. Catching colorectal problems early is one of the best uses of preventive care.
Preparing for Your Colonoscopy
A colonoscopy needs some preparation the day before. Good prep makes the test more accurate.
Your doctor will give instructions, usually including a special diet and a bowel-cleansing routine. Follow them closely so the doctor can see clearly. Arrange a ride home, since you will be sedated. Ask your doctor any questions about the prep beforehand.
Medicare and Colonoscopy FAQs
Is a screening colonoscopy free?
Yes, at $0 when the provider accepts assignment.
How often does Medicare cover one?
Every 10 years for average risk, or every 2 years for high risk.
Why did I get a bill?
Most likely a polyp was removed, which currently carries about 15% coinsurance, or the colonoscopy was diagnostic at 20%.
Is there an age limit?
No. There is no minimum age for the covered screening.
Does Medicare cover the stool tests too?
Yes, and a positive result unlocks a free follow-up colonoscopy as a screening.
Will the polyp charge go away?
Yes. It is scheduled to phase down to $0 by 2030.
