Fixed annuities are typically guaranteed by the insurance company that issues them. When you purchase a fixed annuity, you enter into a contract with the insurance company, and they guarantee to pay you a fixed rate of return on your investment. This means that regardless of how the underlying investments perform, the insurance company is responsible for providing the guaranteed return. The guarantee is backed by the financial strength and claims-paying ability of the insurance company. It's important to note that the guarantees provided by insurance companies are subject to the claims-paying ability of the company. If the insurance company were to become insolvent or unable to meet its obligations, there is a possibility that the guarantees may not be honored. However, insurance companies are regulated by state insurance departments, and there are mechanisms in place to protect policyholders in the event of an insurer's insolvency. It's always a good idea to research and choose a reputable insurance company when considering a fixed annuity.