Abstract This proposal is for ORIP to provide $1,996,700 to construct eight new outdoor pens on the CNPRC south campus. These units will have shade structures and incorporate perches and hanging barrels for primate enrichment. Each enclosure will be equipped with gas fired radiant heaters that are currently being used in the larger outdoor ½ acre corrals. This will allow socialization of juvenile rhesus macaques year round. These new pens will be used for both socialization of Level 1 SPF and Level 2 eSPF rhesus macaques as well as harem breeding to produce an increased number of animals for HIV/AIDS research. These pens will be populated with 16 adult females and two adult males will produce approximately eleven pregnancies each year in each unit. These additional animals will be dedicated to support NIH funded HIV/AIDS funded investigators. The construction of eight new pens will produce over 88 additional animals for AIDS research on an annual basis.