In the US insurance market, coinsurance is the joint assumption of risk between the insurer and the insured. Risk is the potential harm that may arise from some present process or from some future event. ... Insurance is the business of providing protection against financial aspects of risk, such as those to property, life, health and legal liability. ... Insurance, in law and economics, is a form of risk management primarily used to hedge against the risk of potential financial loss. ...

Coinsurance is expressed as a percentage or pair of percentages generally with the insurer's portion stated first. The maximum percentage the insured will be responsible for is generally no more than 50%. Coinsurance indicates how an insurer and an insured will share the costs of a bill that exceeds the insurance policy's deductible up to the policy's stop loss. Once the insured's out-of-pocket expenses equal the stop loss the insurer will assume responsibility for 100% of any additional costs. An Insurance contract determines the legal framework under which the features of an insurance policy are enforced. ... In an insurance policy, the deductible or excess is the portion of any claim that is not covered by the insurance provider. ... The stop-loss policy, in the United States military, is the involuntary retention of troops to remain in service beyond their contractually agreed-upon term. ...

In the international insurance market, coinsurance is the joint assumption of risk between various insurers. Risk is the potential harm that may arise from some present process or from some future event. ... Insurance is the business of providing protection against financial aspects of risk, such as those to property, life, health and legal liability. ...

Coinsurance is generally widely used in the European insurance market. In this context, a common insurance contract is used and the risk is shared based on percentages between the insurance companies. Often, one insurance company will lead. When leading the insurance company will be responsible for administering various aspects of the insurance policy, such as premium, any claims and the insurance documents. In this situation, a charge is levied (termed Lead Office commission).