Over the past decade, the theories of Diffusion of Innovations and of Economics of Standards have been integrated to explain the Diffusion of Standards in Information Technologies. More recently, complex networked technologies unique to particular industries have been identified as a separate category called vertical standards, and the study of their adoption within and across industries has begun. This paper adds to the discourse by developing a theory-based model to explain variance in the adoption of vertical standards by firms. We posit that vertical standards adoption will be influenced by firm-level factors and adopter community-level factors. Key firm-level factors such as prior technology drag, knowledge barriers, and expected benefits, and adopter community-level factors such as standard legitimization and orphaning risk are identified as antecedents of vertical standards adoption. We also identify factors that impact each of these antecedents and put forth a research model interrelating these factors to vertical standards adoption. We expect to test our research model using data collected through a web-based survey of OASIS member firms.