The growth of the number of persons pursuing education outside of their home country has created a relatively new population of transnationally mobile students who experience a pivotal developmental period crossing and across international borders. There are few suitable theoretical models to examine the developmental experiences of this growing population. In his last publication, Urie Bronfenbrenner acknowledged his ecological model was a developmental yet evolving model to be tested and amended by incorporating new evidence. This conceptual paper draws from existing empirical work to advance the ecological model and revise it to be more applicable to and explanatory of developmental experiences of international students in the United States. The resulting model, which we call the "Spanning Systems" model, can be used to identify spaces of potential contradictions or learning in a student's development.