The document provides an overview of social impact bonds (SIBs). SIBs allow private investors to finance social service programs and receive a financial return depending on whether targeted social outcomes are achieved. Over 60 SIBs have been launched globally since 2010, investing over $200 million and impacting over 90,000 lives. The document discusses how SIBs work, highlighting key stakeholders like investors, service providers, and beneficiaries. It also reviews the growth of SIBs and their potential to more efficiently allocate funds by paying for proven social results.