No, worker's compensation is the only required insurance. That said, assuming there is *any* chance of business-related liability--such as from an employee accidently hurting someone during business, including by running into them if driving for business; or from a product or service hurting someone--you really should have liability insurance to protect you. You might also wish to consider insurance on any valuable business property (e.g. computers, office equipment, etc.) or inventory, and "business interruption" insurance to provide income continuation if circumstances force a temporary closure.