Quick Answer
Yes, Medicare Part B covers colonoscopy screenings at 100% - no deductible and no coinsurance - when performed within the approved frequency. If your doctor finds a polyp during a screening colonoscopy and removes it, the procedure changes from screening to diagnostic, and you may owe 20% coinsurance. Medicare Advantage plans must cover the same colonoscopy benefits as Original Medicare.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Screening colonoscopy (average risk) | Covered at 100% | Covered once every 10 years (120 months) for average-risk patients; no deductible or coinsurance |
| Screening colonoscopy (high risk) | Covered at 100% | Covered once every 2 years (24 months) for high-risk patients; no deductible or coinsurance |
| Diagnostic colonoscopy | Partial | Covered at 80%; you pay 20% coinsurance; Part B deductible does not apply |
| Polyp removal during colonoscopy | Partial | Covered but changes procedure to diagnostic; 20% coinsurance applies |
| Medicare Advantage (Part C) | Covered | Must cover same colonoscopy benefits as Original Medicare; cost-sharing varies |
Understanding Your Coverage Options
Original Medicare (Part B) - Screening Colonoscopies
Screening colonoscopies covered at $0 - no deductible or coinsuranceMedicare Part B covers colonoscopy screenings as preventive services, which means there is no deductible and no coinsurance when you receive a screening colonoscopy from a Medicare-participating provider. Medicare also covers the cost of anesthesia for a colonoscopy.
The frequency of coverage depends on your risk level. For average-risk patients, Medicare covers a screening colonoscopy once every 10 years (120 months). For high-risk patients - those with a personal or family history of colorectal cancer, or who have had polyps previously - Medicare covers a colonoscopy once every 2 years (24 months). Medicare also covers a colonoscopy once every 4 years (48 months) following a flexible sigmoidoscopy.
There is no age limit for Medicare coverage of colonoscopies. Medicare will cover a colonoscopy at any age as long as it falls within the approved frequency.
What It Covers
- Screening colonoscopy for average-risk patients - once every 10 years at $0
- Screening colonoscopy for high-risk patients - once every 2 years at $0
- Anesthesia for colonoscopy - covered at $0 for screening procedures
- Colonoscopy following flexible sigmoidoscopy - once every 4 years at $0
What It Doesn't Cover
- Colonoscopies performed more frequently than the approved schedule
- Colonoscopies performed by providers who do not accept Medicare
Screening colonoscopy: $0 (no deductible, no coinsurance). Anesthesia for screening colonoscopy: $0.
Original Medicare (Part B) - Diagnostic Colonoscopies
Diagnostic colonoscopies covered at 80%; you pay 20% coinsuranceIf your doctor finds a polyp or other abnormality during a screening colonoscopy and removes it, the procedure changes from screening to diagnostic. When this happens, different coverage rules apply: Medicare covers 80% of the approved amount, and you are responsible for the remaining 20% coinsurance. The Part B deductible does not apply to colonoscopies.
A diagnostic colonoscopy may also be ordered when you have symptoms such as rectal bleeding, abdominal pain, or changes in bowel habits. In these cases, the colonoscopy is diagnostic from the start, and the 20% coinsurance applies.
If your screening colonoscopy becomes diagnostic, your doctor may ask you to return for another colonoscopy before your standard 10-year interval. That follow-up colonoscopy is also diagnostic, and the 20% coinsurance applies.
What It Covers
- Diagnostic colonoscopy - 80% of approved amount
- Polyp removal during colonoscopy - 80% of approved amount
- Laboratory testing of removed polyps - 80% of approved amount
- Anesthesia for diagnostic colonoscopy - 80% of approved amount
What It Doesn't Cover
- The remaining 20% coinsurance (unless you have Medigap)
Diagnostic colonoscopy: 20% coinsurance; Part B deductible does not apply. With Medigap Plan G, the 20% coinsurance is covered after your annual $283 deductible.
Screening to Diagnostic Conversion
If your doctor removes a polyp during what started as a screening colonoscopy, the procedure is reclassified as diagnostic. This means you will owe 20% coinsurance even though the procedure started as a free screening. Ask your doctor about this possibility before your procedure.
Medicare Advantage (Part C)
Covered - cost-sharing varies by planMedicare Advantage plans are required to cover all colonoscopy screenings that Original Medicare covers, at the same frequency. However, cost-sharing for diagnostic colonoscopies may differ from Original Medicare. Some Medicare Advantage plans may have lower copays for colonoscopies, while others may require prior authorization.
Always verify that your gastroenterologist and the facility where the colonoscopy will be performed are in-network before scheduling the procedure.
What It Covers
- Screening colonoscopies at the same frequency as Original Medicare
- Diagnostic colonoscopies - cost-sharing varies by plan
- Polyp removal - cost-sharing varies by plan
What It Doesn't Cover
- Out-of-network providers (unless your plan allows out-of-network benefits)
- Services requiring prior authorization that was not obtained
Check your plan's colonoscopy cost-sharing
Medicare Advantage plans may have different cost-sharing for diagnostic colonoscopies than Original Medicare. Some plans have $0 copays for colonoscopies; others may charge a copay. Review your plan's Summary of Benefits before scheduling.
Colonoscopy Costs under Medicare (2026)
| Colonoscopy Type | Medicare Coverage | Your Cost (No Supplement) | Your Cost (With Plan G) |
|---|---|---|---|
| Screening (average risk, once/10 years) | 100% - no deductible or coinsurance | $0 | $0 |
| Screening (high risk, once/2 years) | 100% - no deductible or coinsurance | $0 | $0 |
| Screening converted to diagnostic (polyp found) | 80% - no Part B deductible | 20% coinsurance (no deductible) | $0 after $283 annual deductible |
| Diagnostic colonoscopy (ordered for symptoms) | 80% - no Part B deductible | 20% coinsurance (no deductible) | $0 after $283 annual deductible |
| Anesthesia (screening) | 100% | $0 | $0 |
✦ Important Rules for Colonoscopy Coverage
The Part B Deductible Does not Apply to Colonoscopies
Unlike most Part B services, the annual Part B deductible ($283 in 2026) does not apply to colonoscopies - whether screening or diagnostic. For screening colonoscopies, you pay $0. For diagnostic colonoscopies, you pay only the 20% coinsurance, not the deductible. This is an important distinction that can save you money.
The Part B deductible does not apply to colonoscopies. For diagnostic colonoscopies, you owe only the 20% coinsurance - not the $283 deductible.
Cologuard as an Alternative to Colonoscopy
If you prefer a non-invasive colorectal cancer screening, Medicare covers Cologuard - a stool DNA test - once every three years for average-risk patients aged 45–85. Cologuard is covered at 100% as a preventive screening. However, if your Cologuard test is positive, you will need a diagnostic colonoscopy, and the 20% coinsurance will apply to that follow-up procedure.
✦ Frequently Asked Questions
David Haass
AuthorDavid Haass is the Chief Technology Officer and Co-Founder of Elite Insurance Partners and MedicareFAQ.com. He is a member and regular contributor to Forbes Finance Council.
Ashlee Zareczny
ReviewerAshlee Zareczny is a licensed Medicare agent in all 50 states dedicated to educating those eligible for Medicare. She trains agents on CMS compliance guidelines.