Objective. Based on the results achieved to date by the Metropolitan System of Solidarity (SISOL) in Peru, this study undertook to analyze the extent to which SISOL has contributed to innovation in the organization of health services delivery. Methods. SISOL performance indicators were analyzed and compared with those of other health services delivery models in Peru, drawing on data from a survey of 4 570 SISOL users conducted in the last quarter of 2011, National Household Surveys from 2003 through 2011, and statistical data from the Peruvian Ministry of Health and Social Security. Results. SISOL rated high in terms of growth of the demand served in Lima, productivity of human resources in office visits, and levels of user satisfaction. These results are attributed to: (a) the presence of specialists at the first level of care; (b) an innovative public-private structure, as opposed to outsourcing; and (c) a system of incentives based on shared risk management. Conclusions. The findings support the need for primary health care renewal, especially in urban areas to reduce the proliferation of unnecessary levels and sublevels of care. They also point to the possibility of developing synergistic public-private partnerships in which both sectors share risks and act in collaboration within a single service system. And finally, they indicate that primary care needs to be articulated into the segmented models.