Often a commercial insured's liability insurance program consists of several layers. The first layer of insurance generally consists of primary insurance, which provides first dollar indemnity for judgments and settlements up to the limits of liability of the primary policy. Generally, primary insurance is subject to a deductible and obligates the insured to defend the insured against lawsuits, which is normally accomplished by assigning counsel to defend the insured. In many instances, a commercial insured may elect to self-insure. Above the primary insurance or self-insured retention, the insured may have one or more layers of excess insurance to provide coverage additional limits of indemnity protection. There are a variety of types of excess insurance, including "stand-alone" excess policies (policies that contain their own terms, conditions, and exclusions), "follow form" excess insurance (policies that follow the terms of the underlying policy except as specifically provided), and "umbrella" insurance policies (excess insurance that in some circumstances could provide coverage that is broader than the underlying insurance).
The cheapest car insurance, period, will likely carry the minimum coverage required in your state. In most states, this is liability insurance only, which covers property damage and medical bills for others due to accidents you cause. Some states also require uninsured and underinsured motorist coverage, which pay for your injuries or damage if an at-fault driver doesn’t have enough insurance.