American regional accreditation serves two basic functions: quality assurance and quality improvement. Through its public function of quality assurance, accreditation signals to prospective students, parents, employers, and others that the institution meets fundamental standards of quality. Through its private function of quality improvement, accreditation supplies institutions with a useful engine to foster improvement. In this article, the authors discuss the traditional role of institutional research in an institution's preparation for accreditation--a role most aligned with the quality assurance function of accreditation--and suggest two new dimensions to strengthen the role of the institutional research office that are more aligned with the quality improvement function of accreditation. For the traditional role and new dimensions, the authors suggest specific action steps for the institutional researcher. (Contains 1 note.)