Long considered a paragon among low- and middle-income countries in its provision of primary health care, Costa Rica reformed its primary health care system in 1994 using a model that, despite its success, has been generally understudied: basic integrated health care teams. This case study provides a detailed description of Costa Rica’s innovative implementation of four critical service delivery reforms and explains how those reforms supported the provision of the four essential functions of primary health care: first-contact access, coordination, continuity, and comprehensiveness. As countries around the world pursue high-quality universal health coverage to attain the Sustainable Development Goals, Costa Rica’s experiences provide valuable lessons about both the types of primary health care reforms needed and potential mechanisms through which these reforms can be successfully implemented.