<p>At a school like Wash U (as you mentioned) or Wharton, the business school offers both a graduate degree and an undergraduate degree. Both of those schools also require those seeking to major in the business school to apply directly to the business school as a freshman. MIT or U. Mich have another program: at MIT, you are admitted to the institute without consideration of your potential major and you are free to choose a major in the Sloan School of Management if you wish. Northwestern, Harvard, Yale, and Stanford, for example, have only graduate schools of business. You cannot major in business at those four schools, nor can you take classes in the business school as an undergraduate. Admission to the graduate schools of business is based not only on undergraduate performance but also on work experience and other factors. There are no required undergraduate courses per se, unlike medical school. Also, business schools tend to have older students, in the 25-30 age range, who have had some work experience, unlike law or medical schools, which accept students mostly right out of college. Hope that answers your question.</p>