If my my passenger chooses not to wear a seatbelt am I responsible for their injury from an accident?

The first question is whether you were negligent for causing the accident. Assuming you were at fault, a front seat passenger (in Florida) is not entitled to damages for personal injuries caused by his/her failure to wear a seatbelt. However, if she can prove the injuries would have occurred even if she were wearing a seatbelt, or that the seatbelt was defective, or not available for her use, then she can recover damages. You mentioned that you only carry the minimum coverage. By that I assume you only have PIP coverage and no bodily injury liability coverage. Assuming that is correct, unless you have significant assets/income, she will have a hard time even finding a lawyer to take her case. It does not make economic sense for lawyers to make a claim and try to collect damages from most middle income and lower individuals.  This is particularly true in the situation you are describing. However, if she is not the owner of a motor vehicle and does not live with a resident relative who has PIP insurance coverage, she is entitled to have her bills paid under your PIP coverage. That is a no-fault based coverage and it does not matter whether or not she was wearing a seatbelt. You should notify your auto carrier of the accident, particularly if she is going to make a claim against your PIP coverage and absolutely if you have liability coverage. While some people chose not to tell their company to avoid insurance premium increases, a failure to timely notify your carrier can result in denial of coverage for claims brought against you and your policy. This is particularly true with the substandard insurance carriers.    *there are likely facts I am not aware of, so you may want to directly consult with a qualified attorney in your area. Good luck.