PROJECT SUMMARY The U42 SPF4 grant at the Oregon National Primate Research Center (ONPRC) helps to support an active and highly productive HIV/AIDS research program. Significant increases in grant funding and the need for larger group sizes have strained the Center's resources, particularly space and caging. Therefore, additional caging is being requested to support this research by providing optimal long-term housing that better addresses the welfare of the animal subjects that are assigned to projects requiring daily antiretroviral therapy (ART). The ONPRC has multiple caging types, which can broadly be split into two categories: standard cages 32 inches in height with 4.5 sq. ft. of floor space and large cages 36 inches in height with 6- 6.5 sq. ft. of floor space. Larger, taller cages are better suited for promoting positive well-being, and are necessary for social housing adult males over 10kg. ART studies tend to be of long duration resulting in animals often exceeding 10 kg in body weight and therefore requiring the larger size caging. In addition, the cages being requested have been optimized for ease of administration of ART. There is an enlarged opening in the front that allows for the technician to more easily and safely inject the animal, and the squeeze-back mechanism has been refined, compared to older caging to provide better restraint during this procedure. These cages have also been designed to better facilitate the attachment of procedure cages that are used for blood collection. At the ONPRC there are currently 115 macaques assigned to AIDS related research requiring ART. Based on current projections, HIV/AIDS NHP assignments requiring ART could increase to 250 within the next year. The ONPRC is in significant need of new, updated caging for our NHP research areas. This new caging will support HIV/AIDS research by providing right-sized housing that is optimized for macaques requiring daily antiretroviral therapy. Nine one-over-one Socialization Racks (18 cages total) will be purchased to be placed in infectious disease research appropriate animal holding rooms.