If you are a passenger in a vehicle involved in a car accident, you may file an injury claim under both:
You cannot collect from both drivers or owners any more than your total claim is worth, but if one driver or owner does not have insurance to cover your total damages, you can make up the rest against another. And you can collect against the other driver or owner even if that person was not greatly at fault, because as a passenger you weren't at all at fault.
For example, let's say you are a passenger in car X, which has an accident with car Y in which car Y seemed to be most at fault, but car X was also partly to blame. Your total damages are $20,000, but the driver of car Y has only $15,000 worth of insurance coverage. After you collect that $15,000 from car Y driver's insurance, you can collect the remaining $5,000 from car X's insurance.
If either driver was using a car belonging to someone else, you may also look for compensation from the insurance company of the car's owner.
You may not, however, file a liability claim against the driver of the car you are riding in if the driver is a relative with whom you live. In that case, you are considered an "insured person" under liability insurance -- and an insured person cannot file a liability claim against his or her own liability coverage.
In the immediate aftermath of your accident, you may also file a claim under the medical payments coverage of your driver's or owner's auto policy. Medical payments coverage is not based on liability and therefore does not require any discussion with insurance companies about who was at fault. But medical payments coverage does not include compensation for pain and suffering, lost income, or anything other than actual medical bills -- and those only up to the limits of the coverage. If you do collect under medical payments coverage and then later also receive liability compensation from that same insurance company, the amount you collected under medical payments will be deducted from your liability settlement. And sometimes, you're better off using your health insurance instead.
For example, say you are injured in an auto accident and have $2,500 in medical bills in the first two weeks. You can immediately collect that amount under the medical payments provision of the insurance policy of the driver of the car you were riding in. It turns out that the driver of the other car was uninsured, and so you file a liability claim against the driver of the car you were riding in. You settle that claim for a total of $10,000. The settlement amount you actually receive from the insurance company, however, will be only $7,500 -- your $10,000 settlement minus the $2,500 medical payments you received earlier from the same company.
For more tips on filing a claim for injuries after a car accident, and in-depth information on what to expect at every step in your case, get How to Win Your Personal Injury Claim by Joseph L. Matthews (Nolo). And if you're thinking about filing a lawsuit after a car accident, you may want to consider talking with a personal injury attorney to make sure that all your legal bases are covered and your rights are protected.