What the law says
Motorcycle insurance starts with the actual policy. NAIC material warns that motorcycles usually need a separate policy. That means a household auto policy should not be assumed to cover the bike, the rider or a passenger. Read the declarations page and all endorsements.
UM usually means uninsured motorist coverage. UIM usually means underinsured motorist coverage. The exact words, limits, offsets and notice duties come from the policy and state law. A rider should save the motorcycle policy, any household policies, the other driver's information and all denial or reservation letters.
MedPay and health coverage are separate checks. Some motorcycle policies include medical payments coverage, while others do not. Health coverage may pay medical bills, but it can later raise repayment issues depending on the plan and state law. A lawyer can read the papers and explain the order of review.
Florida's no-fault statute is a common trap. Florida section 627.732 defines motor vehicle for no-fault purposes as a self-propelled vehicle with four or more wheels. Sections 627.733 and 627.736 build required security and PIP benefits around that no-fault setup. That is why a motorcycle crash needs a separate coverage check.
The Florida point does not end every coverage question. A motorcycle policy, UM, UIM, MedPay, health coverage, umbrella coverage or the at-fault driver's policy may still matter. The right question is not simply whether Florida PIP applies. It is which policy, if any, responds to this crash.