Upon termination of a given policy, the amount of premium collected minus the amount paid out in claims is the insurer's underwriting profit on that policy. Underwriting performance is measured by something called the "combined ratio", which is the ratio of expenses/losses to premiums.[25] A combined ratio of less than 100% indicates an underwriting profit, while anything over 100 indicates an underwriting loss. A company with a combined ratio over 100% may nevertheless remain profitable due to investment earnings.
To get the cheapest car insurance, start by comparing rates. You can use our list of the Cheapest Car Insurance Companies to see which company has the cheapest rates for your situation. Don’t stop there, however. A company with cheap rates may not have the best service or very satisfied customers. Balance cheap auto insurance rates with the kind of service you want to live with when choosing an insurance company.
In many cases, the legal minimum insurance won’t be enough to cover costs if you cause an accident. If you total someone’s luxury car, for example, their repair costs could easily exceed a $25,000 ceiling. Any damage that surpasses your limits has to come out of your own pocket. That’s why for most drivers it’s wise to select higher limits, such as 100/300/50.

In the United States, the most prevalent form of self-insurance is governmental risk management pools. They are self-funded cooperatives, operating as carriers of coverage for the majority of governmental entities today, such as county governments, municipalities, and school districts. Rather than these entities independently self-insure and risk bankruptcy from a large judgment or catastrophic loss, such governmental entities form a risk pool. Such pools begin their operations by capitalization through member deposits or bond issuance. Coverage (such as general liability, auto liability, professional liability, workers compensation, and property) is offered by the pool to its members, similar to coverage offered by insurance companies. However, self-insured pools offer members lower rates (due to not needing insurance brokers), increased benefits (such as loss prevention services) and subject matter expertise. Of approximately 91,000 distinct governmental entities operating in the United States, 75,000 are members of self-insured pools in various lines of coverage, forming approximately 500 pools. Although a relatively small corner of the insurance market, the annual contributions (self-insured premiums) to such pools have been estimated up to 17 billion dollars annually.[40]
For example, most insurance policies in the English language today have been carefully drafted in plain English; the industry learned the hard way that many courts will not enforce policies against insureds when the judges themselves cannot understand what the policies are saying. Typically, courts construe ambiguities in insurance policies against the insurance company and in favor of coverage under the policy.

Separate insurance contracts (i.e., insurance policies not bundled with loans or other kinds of contracts) were invented in Genoa in the 14th century, as were insurance pools backed by pledges of landed estates. The first known insurance contract dates from Genoa in 1347, and in the next century maritime insurance developed widely and premiums were intuitively varied with risks.[3] These new insurance contracts allowed insurance to be separated from investment, a separation of roles that first proved useful in marine insurance.