NYCETP colleges have been responding to the growing shortage of secondary teachers of mathematics and science in New York City by recruiting from non-traditional sources of teachers - individuals who already possess a baccalaureate in a field related to mathematics and/or science, and are new to teaching in the city's public schools. This pool of prospective teachers has been growing much more quickly than that of undergraduate college students in MST related fields. Many are career changers, and as a group they reflect the cultural diversity of New York City. Many are offered teaching positions even before they have any contact with teacher preparation programs. Many have experienced their disciplines in contexts very different from an urban classroom. The Teacher Opportunity Program (TOP) is designed to facilitate the entry of this pool into teaching in New York City's public schools. TOP is a partnership of the City University of New York and the NYC Board of Education, funded by several private foundations, which is now entering its third year. TOP builds on various prior initiatives - the NYCETP Teaching Scholar program, a fast-track certification program funded by the New York City USI, and the network of relations established by NYCETP, in particular working contacts with the American Museum of Natural History. Introductory summer sessions, to be offered in 2001 at five NYCETP campuses, must respond to the special strengths and challenges presented by this population. A continuing benefit of TOP is the way in which the cohort introduced to the CUNY masters programs in mathematics and science education is motivating continuation and expansion of the curriculum reform initiated by NYCETP for undergraduate programs into masters programs.