Proof of insurance, or proof of financial responsibility, is mandatory in order to legally drive a car in all 50 states and Washington D.C. While a first offense for driving without insurance — or proof of insurance — can yield significant fines, repeated offenses can dramatically escalate the severity of the punishments. Besides legal penalties, if you're in a car accident without insurance, you're liable to be sued by the other driver for the damage to their vehicle and any medical bills they incur from the accident.