The answer to this is it depends on exactly what you are talking about when you say motorhome. In the case of Class A, B or C motorhomes, you’ll need – at a minimum – the state-required amount of vehicle insurance.
Just as is the case with passenger vehicles, some motorists decide to add more protection to RVs for additional peace of mind. If your RV is involved in an accident, the costs for injuries and property damage can add up quickly since an RV is typically much larger than regular passenger vehicles. As the person making the decisions about your vehicle insurance needs, you get to decide the amounts you want to insure up to in coverage.
Additionally, you can choose to buy full coverage insurance, which includes liability, plus collision (your damage costs) and comprehensive (damage caused by other than a car accident, such as theft or fire).