Traditional ecological models are promising for making sense of international student experiences, but the assumed monolithic nature of the structuring systems is inadequate for explaining development that occurs across multiple systems. We present and expand a model called the Spanning Systems Model that recognizes multiple ecologies. The model organizes ecologies in terms of home and host countries, arguing the systems are in some ways independent and in others intertwined. Student experiences are thus structured by both the systems in which the school is located as well as the systems from which the student is coming. Conceptualizing ecologies in this manner shifts the goal of a successful transition into higher education away from acculturation and towards a more complex, case-specific project of identifying areas of alignment and contradiction and tailoring experiences to each student's unique ecologies.