Prematches are offered in October and January prior to official match day in February. If offered a prematch at a school, it means that if you rank that program #1, you will match there on match day. However, you are not obligated to rank the program at #1, and are still able to match at other schools you interview at should you rank them higher. Prematches are typically offered to highly qualified applicants... some schools give out lots of prematches, and others give out only a few and fill the majority of their class on match day in February.