JAIBG funds may be used to develop programs in any of 12 program purpose areas established by Congress. The first of these areas-"building, expanding, renovating, or operating temporary or permanent juvenile correction or detention facilities, including training of correctional personnel"-addresses construction, operation, and training. Before beginning construction, however, jurisdictions should complete a master plan, determine what type of facility will best meet their needs and expectations, and reach a decision to construct. Master planning is a key component because it establishes the specific policies to prevent and reduce crowding and control the length of stay (DeMuro and Dunlap, 1998). To provide practitioners practical guidance and advice on best practices under JAIBG Program Purpose Area 1, this paper addresses five main themes: construction decisions, master planning, facility development, operations, and training.