In 2006, the Massachusetts healthcare reform was introduced to mandate health insurance, extend eligibility of publicly subsidised health insurance, improve quality and access to care and develop preventive health services. The objective of this study was to determine the impact of expanding publicly subsidised health insurance through the Massachusetts reform on access to primary care, disease management and behavioural risk factors. Using cross-sectional data from the Behavioural Risk Factor Surveillance System (BRFSS) from 2001 to 2010 and exploiting the selective introduction of the healthcare reform, we assessed its impact on primary care access, behavioural risk factors, such as obesity, and receipt of diabetes management tests. We did so using a differences-in-differences methodology by comparing Massachusetts with other New England States for 131,002 adults under 300% of the federal poverty level and by race/ethnicity within this group. Triple difference estimates were also conducted to control for potential within state time varying confounding factors. The results suggest that increasing publicly subsidised health insurance had a positive impact on primary care access for lower income adults, particularly those that are white. However, with the exception of improvements in alcohol consumption for one specific group (lower income whites) the reform had no effect on behaviour risk factors or diabetes disease management. The aims of the reform were to improve access to care and through this, behavioural risk factors and diabetes management. This study suggests that while access to care was increased, reducing risk factors attributed to health risky behaviour and diabetes cannot be sufficiently done simply by extending health insurance coverage and the provision of preventive services. This suggests that more targeted interventions are required.