Cardiac rehabilitation (CR) is a multi-disciplinary intervention designed to stabilise, slow, or reverse CVD, restore health following a cardiac event and facilitate the prevention of further events. The Model of Therapeutic Engagement (MTE) is a comprehensive conceptual model for explaining the process of engagement in rehabilitation. Of concern is that the role of socio-environmental factors is absent from explaining individual engagement in the MTE. There is also a lack of prospective studies investigating the impact of socio-environmental barriers on engagement in CR programs over time. This study aimed to expand the MTE, by illuminating the role of socio-environmental barriers in a three-stage process of engagement in CR programs. A prospective study was conducted, with 217 individuals recruited from the Cardiology Ward in the Gold Coast University Hospital (GCUH) and the Robina Cardiac Rehabilitation Centre. The collected data were examined using a structural equation model that added socio-environmental factors into the MTE, using multi-group analyses. In this study, we found that socio-environmental factors were not associated with intention to engage in the CR program, but were related to actual attendance and maintenance of participation in CR programs. Knowing how these socio-environmental barriers affect the process of engagement at different stages may help to tailor more accessible CR programs for the population.