The amount of insurance any particular 18-wheeler may carry varies widely from truck to truck. Some 18-wheelers are part of larger corporations that have substantial assets and large interstate commercial motor vehicle fleets with large commercial motor vehicle policies. Others are local, independent owner-operators that carry only the minimum amount of liability insurance required by law for trucks. Most states require local trucks to carry a minimum of $500,000 per occurrence. Federal law requires higher amounts for vehicles involved in interstate commerce that differ depending on what they are carrying. Normal cargo may only require $750,000 in coverage, while a truck transporting bulk hazardous cargo is required to carry at least $5,000,000. Non-bulk hazardous material transporters and buses must carry $1,000,000 if they travel across state lines. In addition to the minimum coverage required, large companies may carry an umbrella policy to protect the company’s assets from large verdicts.