In Los Angeles and throughout California, it is illegal to drive with a blood alcohol concentration (BAC) of:
0.08% or higher if you're over 21.
0.01% or higher if you're under 21.
0.01% or higher at any age if you are under probation for DUI.
0.04% or higher when driving a vehicle that requires a commercial driver's license.
0.04% or higher when driving a passenger for hire.
That said, regardless of your age, it is also illegal to drive a vehicle in Los Angeles or anywhere in California if you:
have taken excessive alcohol in any form, including medications such as cough syrup;
have taken any drink that affects your driving ability, including prescription and OTC medications; or
have used any combination of drugs and alcohol that limits your ability to drive safely.