When insured parties experience a loss for a specified peril, the coverage entitles the policyholder to make a claim against the insurer for the covered amount of loss as specified by the policy. The fee paid by the insured to the insurer for assuming the risk is called the premium. Insurance premiums from many insureds are used to fund accounts reserved for later payment of claims – in theory for a relatively few claimants – and for overhead costs. So long as an insurer maintains adequate funds set aside for anticipated losses (called reserves), the remaining margin is an insurer's profit.
An insurance underwriter's job is to evaluate a given risk as to the likelihood that a loss will occur. Any factor that causes a greater likelihood of loss should theoretically be charged a higher rate. This basic principle of insurance must be followed if insurance companies are to remain solvent.[citation needed] Thus, "discrimination" against (i.e., negative differential treatment of) potential insureds in the risk evaluation and premium-setting process is a necessary by-product of the fundamentals of insurance underwriting.[citation needed] For instance, insurers charge older people significantly higher premiums than they charge younger people for term life insurance. Older people are thus treated differently from younger people (i.e., a distinction is made, discrimination occurs). The rationale for the differential treatment goes to the heart of the risk a life insurer takes: Old people are likely to die sooner than young people, so the risk of loss (the insured's death) is greater in any given period of time and therefore the risk premium must be higher to cover the greater risk.[citation needed] However, treating insureds differently when there is no actuarially sound reason for doing so is unlawful discrimination.
Certain insurance products and practices have been described as rent-seeking by critics.[citation needed] That is, some insurance products or practices are useful primarily because of legal benefits, such as reducing taxes, as opposed to providing protection against risks of adverse events. Under United States tax law, for example, most owners of variable annuities and variable life insurance can invest their premium payments in the stock market and defer or eliminate paying any taxes on their investments until withdrawals are made. Sometimes this tax deferral is the only reason people use these products.[citation needed] Another example is the legal infrastructure which allows life insurance to be held in an irrevocable trust which is used to pay an estate tax while the proceeds themselves are immune from the estate tax.

Business insurance can take a number of different forms, such as the various kinds of professional liability insurance, also called professional indemnity (PI), which are discussed below under that name; and the business owner's policy (BOP), which packages into one policy many of the kinds of coverage that a business owner needs, in a way analogous to how homeowners' insurance packages the coverages that a homeowner needs.[31]
NerdWallet averaged rates for 40-year-old men and women for 20 ZIP codes in each state and Washington, D.C., from the largest insurers, up to 12 in each state. “Good drivers” had no moving violations on record and credit in the “good” tier as reported to each insurer. For the other two driver profiles, we changed the credit tier to “poor” or added one at-fault accident, keeping everything else the same. Sample drivers had the following coverage limits: