This chapter explores the literature on mortgage discrimination and offers recommendations for future research. It presents a framework for analyzing a lender’s approval or rejection of a loan application. This framework leads to precise definitions of discrimination and redlining. The chapter reviews the literature on loan approval and on defaults, with a focus on the recent study by Alicia H. Munnell and colleagues. It proposes directions for future research on discrimination in loan approval and examines neglected aspects of lender behavior. The chapter provides the discrimination in other types of lender behavior, such as outreach, application processing, and mortgage terms. It explores discrimination by other actors in the mortgage market, including real estate brokers and insurers. Discrimination in the approval of mortgage loan applications is the most dramatic type of lender discrimination, with the most obvious consequences for minority access to housing.