Social impact bonds (SIBs) are financial instruments designed to fund social programs through private investment. In this model, private investors provide upfront capital to implement initiatives aimed at addressing social issues, such as homelessness or education. If the program meets specific performance targets, the government repays the investors with a return on their investment. These bonds aim to improve social outcomes while reducing public spending risks. By linking funding to results, SIBs encourage innovation and efficiency in social services. They represent a collaboration between government, nonprofits, and investors to tackle pressing societal challenges effectively.