IntroductionIn 2003, the Quebec government made important changes in its primary healthcare (PHC) system. This reform included the creation of new models of PHC, Family Medicine Groups (e.g. multidisciplinary health teams with extended opening hours and enrolment of patients) and Network Clinics (clinics providing access to investigation and specialist services). Considering that equity is one of the guiding principles of the Quebec health system, our objectives are to assess the impact of the PHC reform on equity by examining the association between socio-economic status (SES) and utilization of healthcare services between 2003 and 2010; and to determine how the organizational model of PHC facilities impacts utilization of services according to SES.MethodsWe held population surveys in 2005 (n = 9206) and 2010 (n = 9180) in the two most populated regions of Quebec province, relating to utilization and experience of care during the preceding two years, as well as organizational surveys of all PHC facilities. We performed multiple logistical regression analyses comparing levels of SES for different utilization variables, controlling for morbidity and perceived health; we repeated the analyses, this time including type of PHC facility (older vs newer models).ResultsCompared with the lowest SES, highest SES is associated with less emergency room visits (OR 0.80) and higher likelihood of at least one visit to a PHC facility (OR 2.17), but lower likelihood of frequent visits to PHC (OR 0.69), and higher affiliation to a family doctor (OR 2.04). Differences remained stable between the 2005 and 2010 samples except for likelihood of visit to PHC source which deteriorated for the lowest SES. Greater improvement in affiliation to family doctor was seen for the lowest SES in older models of PHC organizations, but a deterioration was seen for that same group in newer models.ConclusionsDifferences favoring the rich in affiliation to family doctor and likelihood of visit to PHC facility likely represent inequities in access to PHC which remained stable or deteriorated after the reform. New models of PHC organizations do not appear to have improved equity. We believe that an equity-focused approach is needed in order to address persisting inequities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12939-015-0243-2) contains supplementary material, which is available to authorized users.