Key social and emotional milestones during adolescence are often directly related to the abilities to initiate and maintain intimate relationships, maintain physically maturing bodies, and manage personal sexuality. Most adolescents with developmental disabilities have particular difficulty expressing sexuality in satisfying ways, consequently facing issues such as limited intimate relationships, low self-esteem, increased social isolation, deregulated emotional maintenance, reduced sexual functioning, and limited sexual health. Appropriate sexual knowledge assists not only in achieving personal fulfillment, but protection from mistreatment, abuse, unplanned pregnancies, or sexually transmitted diseases (STDs). It also works to help solve problems of loneliness and problems with self-esteem. This book will address this but also much more. Issues of physical and cognitive development will be discussed, including appropriate sexual development/urges and brain development, and innate similarities and differences of sexuality that could occur between people with autism spectrum disorders and intellectual or developmental disabilities, including the complexities of physical disabilities. The authors will also consider special considerations for group homes and recreational facilities, and specifically focus on concepts of ethics and models of consent (medical, legal, social, and educational), as well as how to deal with uncertainty.