The Annie E. Casey Foundation has developed this practice guide to support Juvenile Detention Alternative Initiative (JDAI) sites in meeting their obligation to ensure the safety and well-being of lesbian, gay, bisexual and transgender (LGBT) youth involved in the juvenile justice system. The guide covers a wide range of policies and practices -- from broad organizational measures such as staff training and nondiscrimination policies, to specific practices such as talking with youth about sexual orientation and gender identity and making individualized classification and housing decisions. This guidance is critical because LGBT youth are at heightened risk of physical, sexual and emotional abuse, particularly in secure settings. In addition, LGBT youth represent up to 20 percent of detained youth -- a far greater percentage than their share of the general population. Although the guide is chiefly aimed at promoting the health and well-being of LGBT youth, its recommendations will benefit all justice-involved youth by exposing and challenging bias, promoting mutual respect and increasing professionalism.