A second DUI (Driving Under the Influence) offense generally carries more severe penalties than a first offense, varying by state but often including mandatory jail time, higher fines, longer license suspension, and mandatory installation of an ignition interlock device (IID). For instance, in many states, you could face jail time from a few days up to a year, fines that can escalate into thousands of dollars, and license suspension periods that might last from one to several years. Some states also impose mandatory alcohol education or treatment programs. The specifics depend on state laws, the time elapsed since the first offense, the BAC (Blood Alcohol Concentration) level at the time of arrest, and whether there were aggravating factors like accidents or minors in the vehicle. Consulting with a DUI attorney is highly recommended to navigate the complexities of these laws and potentially mitigate the consequences.