To figure out what insurance company is responsible for your medical bills and lost wages will depend on what state you reside and the type of insurance they require motorists to carry. The main differences depend on if your state is a no-fault state or not. Personal Injury Protection (PIP) is generally used in a no-fault state for a situation like this.

For example in Michigan, which is a no-fault state, if you are injured as a passenger in a car crash typically your own car insurance would pay your benefits. But in a situation like yours where you do not have auto insurance you would collect the benefits from the insurance company that covered any vehicle owned by a relative that you live with. If you did not have coverage that way either than you would collect from the insurance company covering the car or driver in which you were riding.

If you are in a state without no-fault laws you typically would be able to put your injury claims through the at-fault person's bodily injury liability policy. You can find out your state's insurance laws by contacting the state's insurance regulatory body.