The Salud Mesoamerica Initiative (SMI) was a public-private regional partnership aimed at reducing inequities in access to and the quality of reproductive, maternal, neonatal, and child health (RMNCH) services in eight countries across Central America and Mexico. This initiative was a collaboration between the governments of these countries, the Bill Gates Foundation, the Carlos Slim Foundation, the governments of Canada and Spain, and the Inter-American Development Bank (IDB), which acted as the general administrator of the trust fund. The program sought to strengthen public health systems by employing a results-based financing (RBF) model while also providing technical assistance to improve RMNCH services, with Ministries of Health (MoHs) taking the lead in implementation through their existing personnel and infrastructure. SMI leveraged approximately $175 million from donor and national resources, organizing its operations into two- to three-year phases in each country. The model involved setting ten indicators and targets for each phase, with agreed-upon interventions funded through a combination of national and donor contributions. Ministries of Health were eligible to receive financial incentives amounting to about 50% of their initial investment if they met their targets, which were independently verified through household and health facility surveys conducted by the Institute for Health Metrics and Evaluation at the University of Washington. While the donor funds were catalytic, contributing less than 1% of the annual health budgets of participating nations, they played a crucial role in initiating and guiding interventions. The program's indicators and targets evolved in complexity over time, beginning with improvements in health system readiness—such as updating clinical guidelines and ensuring the availability of essential supplies—before progressing to more ambitious goals related to clinical quality, service coverage, and effective health intervention implementation.