Restrictive housing within U.S. jails and prisons began as a rehabilitative initiative in the 1800s. Today, few would say it offers much therapeutic benefit. At best, it is a behavioral management tool essential for maintaining security; at worst, it is a place of human suffering. Though its nature and purpose can vary across institutions, restricted housing is intended to separate individuals who present a heightened risk to the safety of the institution, others, or themselves from the general population. The debate over restricted housing—between academics, advocates, legal professionals, correctional personnel, and the public—has raged on since the early days of its implementation. However, most scholars and experts involved in the discussion can agree it is an overused practice, and efforts are grossly needed to prevent, divert, or transition people out of restricted housing as quickly as possible without compromising the welfare of others. This chapter attempts to synthesize the complex issues surrounding the practice of restricted housing, including its historical foundations, its effectiveness as a management strategy, relevant case law, research on its psychological consequences, and newer initiatives to better address the needs of individuals who are at greater risk of being placed in restrictive housing.