This paper is intended to document the development of the Mathematics across the Curriculum (MAC) movement, following a mathematics problem solving model. Of course, just as new, related problems often arise after we have completed the solution of a current mathematics problem, so too, many questions remain regarding the future of MAC. Although preliminary assessments have been favorable, no broad-based evaluation of the impact of MAC has been conducted. To what extent has the promise of increased student understanding of mathematics and its connections to other disciplines been realized? What can be done to overcome logistical obstacles preventing instructors from working together in real schools settings? Are changes in institutional culture and relationships among academics merely transitory? Is the development of a strong base of curricular materials forthcoming? In other words, will MAC reach a level of educational permanence, or ultimately be discarded as another interesting, but unmanageable instructional fad?