Doctor shortage is a constant problem in smaller cities and towns, which tend to be more vulnerable from a social and economic point of view, and located in geographically isolated areas. The goal of this study was to establish the share and characteristics of the small cities and towns in the macro-region of northern Paraná that subscribed to the Mais Médicos para o Brasil (PMMB) program. This is a quantitative study of 82 cities and towns using primary and secondary data. Results show that only a few of them (6.1%) had any adherence criteria, which was not an impediment for other cities and towns (75%) to adhere to the project. Cities and towns with over five thousand inhabitants, lower municipal HDI (Human Development Index), some adherence criteria and more geographically isolated, either from the main city in the region or the closest large or mid-sized city, tended to adhere to the PMMB. It is undeniable that the PMMB significantly reduced the uneven distribution of doctors in Brazil and the study region. However, the sustainability of this policy is linked to addressing other remaining challenges in the SUS system.