Coupled systems comprise multiple interacting subsystems and are an increasingly common computational science application, most notably as multiscale and multiphysics models. Parallel computing and, in particular, message-passing programming have enabled the development of these models but also present a parallel coupling problem (PCP) in the form of intermodel data dependencies. Component-based software engineering has been proposed as one means of conquering software complexity in scientific applications; and given the compound nature of coupled models, it is a natural approach to addressing the PCP. We define re component specification for solving the PCP, abstracting the elements of the PCP and mapping them onto a set of components from the Common Component Architecture. We discuss a reference implementation based on the Model Coupling Toolkit. We demonstrate how these components might be deployed to solve coupling problems in climate modeling.