According to the GMAT official website, more than 4,800 graduate management (MBA) programs around the world use the GMAT as part of their admissions selection process. Even business schools such as the University of Pennsylvania's Wharton School, which claim that they don't have a minimum GMAT requirement, temper their words carefully. "GMAT scores have proven to be a useful predictor of success in the quantitative courses that are an important foundation for the MBA program," according to the Wharton site.