Can a health insurance company refuse to pay medical costs if their insured is injured but found at fault for auto accident?

Health insurance is supposed to cover you absent very limited circumstances like pre-existing conditions. I have not heard of an insurance company directly refusing coverage due to a DUI. However, if you are considered high risk and the issue of alcohol and driving under the influence was a repeat occurrence, it could possibly be denied. Check your individual contract or group contract for provisions dealing with insurance coverage denial and if you can't locate the provision, file a complaint with your state's department of insurance. You can also go through the appeal process of your insurance provider, and make sure to obtain in writing from the provider why exactly it refuses coverage (the DUI directly or indirectly).