PRIMARY: To identify, characterize, and co-enroll HIV-infected adolescents into existing and future ACTG (or other NIH-sponsored) HIV treatment protocols through the systematic and recurrent assessment of eligibility. To assess the ability of adolescents enrolled in ACTG 220 to adhere to ACTG (or other NIH-sponsored) HIV treatment protocols; and to define factors that influence the adolescent's ability to enter or adhere to study protocols.