One reason you could get a bill: At least one provider included in the procedure is not in your insurer’s network. By Kimberly Lankford, Contributing Editor April 28, 2014 My wife had a colonoscopy, which we thought was a preventive-care procedure that was not subject to her health insurance deductible or co-payments. But we just got a bill for $700. Any idea why?SEE ALSO: Cut Your Risk, Cut Your Insurance Rates You’re right that most health insurance policies must cover certain tests, vaccines and other preventive care (including colonoscopies for people age 50 and older) without any cost-sharing, even if you have a high-deductible policy. See Preventive Care Without Cost-Sharing for more information on what is covered. But some people have been getting unexpected bills for preventive care -- especially for colonoscopies. That can happen when a provider included in the procedure is not in your insurer’s network. For example, the doctor and hospital might be in your network, but the anesthesiologist might not be. Before you sign up for a procedure, ask whether all the providers involved are in your insurer’s network. Sponsored Content Using out-of-network providers may cost you more in coinsurance, and their services may be subject to a separate, higher deductible than the services of your insurer’s in-network providers. The out-of-network provider may also charge more than your insurer’s negotiated rate, and you could be on the hook for the difference. (If you belong to an HMO, you might not have coverage for out-of-network providers at all, except in an emergency.) Most insurers have tools to help you look up providers that are in-network. It also helps to ask the doctor’s office yourself because the lists can change. You could also receive a surprise bill if a preventive test reveals something suspicious that the doctor needs to send to a lab for testing. “The best example is colonoscopy,” says Tom Bridenstine, managed care ombudsman for the Virginia Bureau of Insurance. “When a person goes in for a screening and they find a polyp that they biopsy, the coding can be changed from ‘preventive’ to ‘diagnostic,’ and charges may be applied to the deductible.” The practice may vary depending on the insurer. Advertisement If you are billed for a preventive procedure that you thought was fully covered, first contact your insurer for an explanation. You can also contact your state insurance department; your explanation of benefits may include contact information for your insurance department’s consumer assistance program, or you can go to www.naic.org for links to each state’s insurance department. In response to consumer complaints, a few states have passed laws requiring insurers to code colonoscopy as a preventive procedure that is not subject to a deductible, as long as the test was originally intended as a screening.(The Kaiser Family Foundation conducted a study that examined unexpected charges for colonoscopies.) Got a question? Ask Kim at email@example.com.