In California penalties are usually increased if a person is convicted of a DUI with a breath or blood alcohol level of over .15%. Additional penalties can include a longer alcohol education program, a requirement to install in the defendants vehicle an ignition interlock device, plus higher fines and even county jail time in some jurisdictions.

MADD carries a great deal of influence in California and has been lobbying for tougher sentencing in DUI cases for many years. It keeps a close eye on judges and prosecutors and their record in dealing with DUI cases. Penalties for DUI in California are increased almost every year largely as a result of MADD. However, MADD'S lobbying efforts and increasing penalties seemingly have little impact on the number of people arrested for DUI in Los Angeles and Statewide.