The Sustainable Development Goals (SDGs, or Global Goals) and their associated targets set out by the United Nations in 2015 explicitly seek to address some of the largest challenges facing children around the world. Early Childhood Development (ECD) interventions have been found to improve adult health and education levels, reduce crime, and raise employment rates, all of which will be paramount to achieving global economic, climate, and physical security. Achieving the ambitious early childhood-related SDGs will require substantial increases in the volume and effectiveness of resources. Contingent disbursement or Payment by Results (PbR) mechanisms reward the delivery of one or more outputs or outcomes upon verification that agreed upon results have been achieved. PbR mechanisms by definition have at least some payment contingent on outcomes (e.g., reduction in disease) or outputs (e.g., vaccinations delivered, also known as fee-for-service), though some also provide a portion of funding for inputs (e.g., vaccines delivered to clinics). While some PbR mechanisms have been used to finance early childhood initiatives, social and development impact bonds have yet to be used in the early childhood sector in LMICs. Given the exploding interest in both impact investing and PbR mechanisms and the critical need to think creatively about financing services for young children, this study seeks to explore the potential to use this tool to make some headway in achieving the outcomes laid out in the SDGs. The following are appended: (1) Contributors; (2) Inventory of Early Childhood Interventions with Evaluations; (3) Outcome Measurement Tools: (a) Outcome Metrics for the Social Impact Bonds for Preschool Education in the United States; (b) Outcome Metrics for Early Childhood Development (Global); and (c) International, Regional, and Cross-National Education Assessment Instruments and Initiatives; and (4) Innovative Financing Mechanisms. [For the Policy Brief, "Policy Recommendations on Impact Bonds for Early Childhood Development in Low- and Middle-Income Countries. Policy Brief," see ED568956.]