The unified 2005 Specification of the American Institute of Steel Construction (AISC) is a considerable departure in form from previous editions of the Specification. Its format permits both Load and Resistance Factor Design (LRFD) and Allowable Strength Design (ASD). This is accomplished by presenting nominal resistances for the various limit states and then obtaining the available resistance either by multiplying by a resistance factor for LRFD or dividing by a safety factor forASD. Provisions for the design of HSS members and connections are included in the 2005 Specification instead of appearing in a separate specification as in the past. Including HSS provisions along with those for other shapes leads to uniformity in design methodology for all structural members, but also produces a complex appearing document. However, the various sections have been subdivided and arranged so that it is possible to extract HSS provisions without being overwhelmed with other requirements. This paper presents an overview of the 2005 Specification format, with emphasis on the new HSS provisions.