If you don't have PIP and you're in an accident that's your fault, you'll be responsible for the other person's medical expenses. If you don't have an insurance policy to cover this, you may have to pay for their medical expenses out-of-pocket.
Remember, PIP insurance isn't available in all states. PIP limits typically range from $1,500 to $250,000. This depends on the law in the state, as well as the injuries that occurred.