Driving under the influence of drugs or alcohol is a serious offense. If you are convicted of DUI, you are subject to suspension or revocation of your driver license, heavy court fines and other penalties, or even incarceration. If your license is suspended, you cannot be insured to use a vehicle because you cannot legally drive.
If you are one of the lucky few who do not lose their license, you will still need to carry a special insurance certificate, called an SR-22, for anywhere from 1 to 5 years. Since an SR-22 is purchased from a car insurance company, your insurance company would know about the DUI when you applied for an SR-22. Since a DUI conviction makes you a higher risk on the roads, you can expect your insurance premiums to increase as well.
Unlike most traffic offenses, a DUI stays on your driving record for the rest of your life. For insurance companies, however, the effects of the DUI are much shorter because most auto insurance companies only look at the past 3 years of your driving record. After that time, a DUI's on your driving history would not be counted against your driving risk.
If your insurance is up for renewal and the DUI has not yet been reported to the insurer, it will be discovered during the renewal review. So you may be able to drive for a few months without the insurance company finding out, but eventually the DUI is going show up, and you are going to be faced with higher premiums.
To offset the increase in insurance cost, you can take a voluntary driver improvement course. Most insurance companies give you a discount for taking the course, spread out over a period of 3 to 5 years. This discount is mandatory in some states, so check with your state DMV or Department of Insurance to find out about your location.