The highest college degree given by universities in the U.S. is the Ph.D or other equivalent research doctorates, according to the American Graduate Education website. Professional doctorates, such as a doctor's M.D. degree or a lawyer's J.D. degree, are not quite the equivalent.
To receive a research doctorate, one must complete coursework, take comprehensive exams, choose an original research topic, have that topic approved by an academic committee, complete a doctoral dissertation and defend that dissertation before a committee. While Ph.D is the most common designation for the research doctoral degree, equivalents include the D.M., or Doctor of Music; the D.Arch., or Doctor of Architecture; and the D.S.W., or Doctor of Social Work.