The market categories literature is reaching the adolescent stage. In order to “look forward” and chart the next stages of this literature’s growth, we first need to “look back” at what we have learned so far. We thus begin with a systematic review of the literature on market categories from the 1990s to the present. Our search of leading management and sociology journals yielded 100 empirical papers, which we group into eight themes. We then discuss in more detail the findings under the top three of these themes: category spanning, new category construction, and category change. Based on our review, we then “look forward” and offer suggestions for future research on market categories. Specifically, we call for more explicit attention to 1) agency, particularly in studies of category spanning, 2) market categories at the intersection of multiple institutional logics, 3) market categories as an outcome rather than antecedent, and 4) construct clarity and consistency. We hope these recommendations will ensure a long and healthy future for this burgeoning literature.