Access to universal health coverage is a fundamental right that ensures that even the most disadvantaged receive health services without financial hardship. The Democratic Republic of Congo is among the poorest countries in the world, yet healthcare is primarily made by direct payment which renders care inaccessible for most Congolese. Between 2017 and 2021 a purchasing of health services initiative (Le Programme de Renforcement de l’Offre et Développement de l’accès aux Soins de Santé or PRO DS), was implemented in Kongo Central and Ituri with the assistance of the non-governmental organization Memisa Belgium. The program provided funding for health system strengthening that included health service delivery, workforce development, improved infrastructure, access to medicines and support for leadership and governance. This study assessed the social and health impacts of the PRO DS Memisa program using a health impact assessment focus. A documentary review was performed to ascertain relevant indicators of program effect. Supervision and management of health zones and health centers, use of health and nutritional services, the population’s nutritional health, immunization levels, reproductive and maternal health, and newborn and child health were measured using a controlled longitudinal model. Positive results were found in almost all indicators across both provinces, with a mean proportion of positive effect of 60.8% for Kongo Central, and 70.8% in Ituri. Barriers to the program’s success included the arrival of COVID-19, internal displacement of the population and resistance to change from the community. The measurable positive impacts from the PRO DS Memisa program reveal that an adequately funded multi-faceted health system strengthening program can improve access to healthcare in a low-income country such as the Democratic Republic of Congo.