Felony DUI laws in the United States escalate a driving under the influence (DUI) charge from a misdemeanor to a felony based on specific circumstances. These include having multiple prior DUI convictions within a certain period, often three or more in ten years, causing injury or death in an accident while intoxicated, driving with an extremely high blood alcohol content (often above .16%), or operating a vehicle under the influence with minors onboard. A felony DUI conviction leads to significantly harsher penalties than a misdemeanor, including longer prison sentences, higher fines, extended or permanent license revocation, mandatory installation of ignition interlock devices, and potentially lifelong consequences like loss of voting rights or difficulty in securing employment. The exact criteria for a felony DUI can vary by state, making it critical to understand local laws or consult with a legal professional if charged.