Runoff Business refers to the management of insurance policies by insurers once they have stopped underwriting new policies. In other words, it is the process of transferring and managing the liabilities of insurance policies that were written in the past and are no longer in force.

In the insurance industry, insurance companies can enter into runoff for a variety of reasons such as mergers, acquisitions, or changes in business strategy. Once an insurer enters into a runoff, it essentially stops writing new insurance policies and focuses on managing its existing book of business. The insurer's goal is to ensure that all claims are handled and all policyholders are ultimately satisfied.

The management of runoff business is often complex and requires expertise in actuarial science, underwriting, and claims management. Insurers typically set aside reserves to pay for future claims, and they may for instance transfer some or all of their liabilities to a third-party insurer. Insurers may also seek out alternative capital and innovative ways to spread the risk, such as through reinsurance or structured reinsurance transactions.

In summary, the runoff business is an important part of the insurance industry that deals with the management of policies after they have been written. It involves complex risk management strategies to ensure that policyholders are adequately protected and that insurers are able to meet their obligations.