Most private health plans must cover recommended preventive care with no cost sharing when you use an in-network provider. That includes a yearly checkup or a screening colonoscopy. A bill usually comes for one of three reasons. The office billed a second “problem” visit for a new issue you raised. A diagnosis code turned the service into diagnostic care. Or a lab or service wasn’t on the preventive list. Some of these charges are legitimate and some are coding errors. Ask for an itemized bill and your visit note, then use the coding review letter below.
Preventive care is care meant to prevent illness or catch it early, like checkups, screenings and vaccines. The no-cost rule comes from the Affordable Care Act. HealthCare.gov puts it carefully: preventive services are “generally” free in network, but “$0 cost isn’t guaranteed in all cases.” The billing codes decide which case you’re in.
Key takeaways
- If a preventive service isn’t billed separately from the office visit and the visit’s main purpose was prevention, your plan can’t charge cost sharing for the visit (45 CFR 147.130).
- Raising a new problem can add a separate office visit with modifier 25. UnitedHealthcare’s 2026 commercial policy, for example, pays the preventive visit plus 50% of a separate problem visit billed with modifier 25.
- Removing a polyp during a screening colonoscopy is part of the screening, and so is anesthesia when the provider decides it’s medically appropriate, according to the federal ACA FAQs.
- A follow-up colonoscopy after a positive stool test must also be covered without cost sharing for plan years starting on or after May 31, 2022.
How this guide was checked: rules come from the eCFR, HealthCare.gov, the Department of Labor’s ACA FAQs, CMS and the FY2026 ICD-10-CM guidelines. Last reviewed 4 October 2026. This is educational content, not legal or medical advice.
Table of Contents
Why a “free” checkup ends up on a bill
1. A second visit was billed for a problem
A yearly checkup is billed with a preventive medicine code (CPT 99381 to 99397, by age and new or established patient). If you also bring up a new or worsening problem, like back pain or a medication change, the doctor may bill a separate problem-oriented visit (for example, CPT 99213) with modifier 25. That modifier tells the insurer the extra visit was “significant and separately identifiable.”
That second visit is where your copay, deductible or coinsurance comes from. It can be correct. But if the problem was minor and handled in a minute, the separate visit may not belong on the claim. UnitedHealthcare’s commercial policy says it won’t pay a problem visit that isn’t significant and separately identifiable.
2. The diagnosis code made it diagnostic
The federal rule depends on how the visit was billed. If a preventive service is billed separately from the office visit, the plan may charge for the office visit. If it isn’t billed separately, the plan can charge for the visit only when its main purpose wasn’t preventive care.
3. A test wasn’t on the preventive list
Preventive coverage is tied to specific recommended services: U.S. Preventive Services Task Force “A” and “B” ratings, recommended vaccines and certain women’s and children’s services. A lab test ordered to check a symptom or watch a known condition isn’t preventive, even if it’s drawn at your physical.
In June 2025, the Supreme Court upheld the Task Force’s structure in Kennedy v. Braidwood Management, so the no-cost preventive coverage rule stayed in place. The Court sent the case back to the lower courts for further proceedings.
Screening vs diagnostic colonoscopy: what the codes say
Colonoscopies cause the most confusing bills. Here’s how billing offices code them.
| Situation | Codes billers commonly use | What you should pay (private plan, in network) |
|---|---|---|
| Routine screening, nothing found | ICD-10 Z12.11 (screening for colon cancer). Many offices add modifier 33 (preventive service) | $0 |
| Screening, polyp found and removed | Z12.11 first, then K63.5 (polyp of colon) as an additional code | $0 for the polyp removal under the ACA FAQs |
| Follow-up after a positive stool test | Varies by insurer. Ask the office how it was coded | $0 for plan years starting on or after May 31, 2022 |
| Colonoscopy for symptoms, like bleeding | Symptom or condition code first | Normal cost sharing may apply |
The FY2026 ICD-10-CM guidelines cover this case: “Should a condition be discovered during the screening then the code for the condition may be assigned as an additional diagnosis.” So finding a polyp shouldn’t push the screening code out of first place. If the polyp code is listed first and the screening code is missing, ask for a coding review.
Medicare works differently
Traditional Medicare uses its own codes (like G0121 for a screening colonoscopy when you’re not high risk) and a PT modifier when a screening turns diagnostic or therapeutic. CMS says that in that case the Part B deductible is waived, and coinsurance is 15% for 2023 to 2026, 10% for 2027 to 2029 and 0% starting in 2030. So a small coinsurance on a Medicare colonoscopy with polyp removal can be correct in 2026.
Step-by-step: what to do about the bill
- Compare the bill to your EOB. Find which line has cost sharing. Our guide on how to read an Explanation of Benefits shows where to look.
- Ask the provider for an itemized bill with codes. You want the CPT codes, modifiers and diagnosis codes for each line.
- Ask for your visit note or procedure report. It shows what the doctor documented, including any problem discussed.
- Check the codes against the table above. Look for a problem visit with modifier 25, a missing Z12.11 or modifier 33, or a symptom code listed first.
- Send the coding review letter. Ask the office to review the coding and, if it’s wrong, send a corrected claim. Our corrected claim guide shows how offices do that.
- If the coding is right but the plan still charged you, appeal to the insurer. Point to the preventive-care rule and the ACA FAQs.
- Ask the office to hold the balance while the review is open.
Codes like CO-4 (modifier doesn’t match the procedure) show up in our denial code list, along with a page on CO-4 modifier denials.
Free template: request for a coding review of my preventive visit
[Your name] | [Address] | [Phone] | [Date of birth]
[Date]
[Practice or facility] - Billing / Coding Department
[Address]
Re: Coding review request - preventive visit
Account #: [ ] Date of service: [ ] Insurer claim #: [ ]
I was billed $[amount] for what I scheduled as a preventive
[annual physical / screening colonoscopy]. My EOB shows cost
sharing on [line or code].
Please:
1. Send me an itemized statement listing the CPT/HCPCS codes,
modifiers and ICD-10 codes billed.
2. Send me the visit note or procedure report for this date.
3. Review whether the coding matches the documentation, including:
- whether a separate problem visit (modifier 25) was supported;
- for a screening colonoscopy, whether the screening code
(Z12.11) and modifier 33 were reported, with any finding,
such as a polyp, listed as an additional diagnosis.
4. If a correction is needed, submit a corrected claim to my
insurer.
5. Hold my account from collections during the review.
Thank you,
[Signature]Preventive visit prep checklist
- ☐ Confirm the doctor or facility is in network for preventive care
- ☐ When you book, say “preventive” or “screening” visit
- ☐ Ask whether any planned labs are preventive or diagnostic
- ☐ If you want to discuss a new problem, ask whether it’ll be billed as a separate visit
- ☐ For a colonoscopy, ask how anesthesia and pathology will be billed and whether they’re in network
- ☐ Keep your EOB and compare it to any bill before you pay
If anesthesia or pathology came from an out-of-network provider at an in-network facility, see our guide to the No Surprises Act and out-of-network anesthesia.
FAQ
Why was I charged for my annual physical?
Usually because a separate problem visit was billed with modifier 25, a test wasn’t on the preventive list, or a diagnosis code made part of the visit diagnostic. Ask for an itemized bill and your visit note to see which one applies.
Can my doctor bill a preventive visit and a sick visit on the same day?
Yes, if the problem needed significant, separately identifiable work. Insurers set their own payment rules. UnitedHealthcare’s commercial policy pays 50% of a problem visit billed with modifier 25 alongside the preventive visit.
My screening colonoscopy found a polyp. Should I owe money?
Under a private plan, generally no. The federal ACA FAQs say polyp removal during a screening colonoscopy is part of the preventive service and can’t have cost sharing. Medicare is different: a reduced coinsurance applies in 2026.
Is a colonoscopy after a positive stool test free?
For private plans, yes, for plan years starting on or after May 31, 2022. The Department of Labor’s ACA FAQs say the follow-up colonoscopy is part of the screening.
Is preventive care still free after the Braidwood case?
The rule is still in place. On June 27, 2025, the Supreme Court ruled in Kennedy v. Braidwood Management that the Task Force members were properly appointed, and sent the case back to the lower courts for further proceedings. Check HealthCare.gov for the current list of covered services.
Related patient guides
Disclaimer: This article is educational and is not legal, medical or coding advice for your specific claim. Preventive coverage depends on your plan (grandfathered plans and Medicare follow different rules), your age and risk factors, and how your care was documented. Contact your provider and insurer about your claim, and check each linked source, since rules can change.
Written by Manikandan, RCM specialist at Medical Billing 101.
Sources
- eCFR, 45 CFR 147.130, Coverage of preventive health services, retrieved 4 Oct 2026.
- HealthCare.gov, Preventive care benefits for adults, retrieved 4 Oct 2026.
- U.S. Department of Labor, FAQs about ACA Implementation Part 47 and Part 51, retrieved 4 Oct 2026.
- UnitedHealthcare, Preventive Medicine and Screening Policy, Professional (Commercial), policy 2026R0013C, retrieved 4 Oct 2026.
- CMS, MLN MM12656, Colorectal Cancer Screening Tests: Changes to Coinsurance for Related Procedures, retrieved 4 Oct 2026.
- CMS, ICD-10-CM Official Guidelines for Coding and Reporting FY2026, retrieved 4 Oct 2026.
- Supreme Court of the United States, Kennedy v. Braidwood Management, Inc., No. 24-316 (June 27, 2025), retrieved 4 Oct 2026.
Manikandan is a Revenue Cycle Management (RCM) specialist with over 10 years of hands-on experience in US healthcare billing. He has worked extensively with commercial payers, Medicare, and Medicaid across multiple specialties including surgery, orthopedics, and radiology. Manikandan founded Medical Billing 101 to provide free, accurate denial code guides, CPT coding references, and Medicare billing resources for US medical billing professionals.
