Amid the increased utilization of ride-sourcing, the relationship between these services and public transit received significant attention from policymakers and researchers. Prior studies have found that ride-sourcing has mixed impacts on transit ridership and that transit use tends to be positively associated with ride-sourcing use. However, these studies have primarily treated transit use and transit pass ownership as explanatory variables. Given the potential for ride-sourcing to influence transit use, further work is needed to understand the relationship between these services. To explore whether transit pass ownership is a source of heterogeneity among ride-sourcing users, this study uses an econometric model to explore the impacts of transit pass ownership on the determinants of ride-sourcing use in Metro Vancouver. Using data from a web-based survey, a two-stage model is used to jointly model transit pass ownership, ride-sourcing adoption, and ride-sourcing frequency. The results demonstrate the potential for transit pass ownership to be a source of heterogeneity among ride-sourcing users. Specifically, the factors influencing ride-sourcing use (and the elasticity of these factors) were found to differ based on transit pass ownership. Additionally, the results suggest that attitudes and perceptions toward ride-sourcing can influence transit pass ownership. These findings can help inform targeted approaches to limiting the negative impacts of ride-sourcing on transit use.