The objective of this document is to understand the potential that voluntary savings has to increase pension coverage for low-income and independent workers in Chile, Colombia, Mexico, and Peru. It comprehensively reviews supply, demand, and institutional barriers to retirement savings, and presents possible cost-effective solutions to overcome these barriers. The framework of solutions proposed consists of behavioral tools, in addition to financial and technological innovations, with high potential for impact on the long-term savings of independent and low-income workers.