This report covers design and construction of 30 in. (760 mm) diameter or larger foundation piers constructed by excavation of a hole in a subgrade that is later filled with concrete. The 30 in.(760 mm) diameter boundary is an arbitrary size; smaller-diameter drilled piers can be designed and installed in accordance with ACI 543R. Although determination of overall pier size and concrete section design are two basic drilled pier design procedures, emphasis is focused on the determination of overall pier size, which is affected by the interaction between subgrade and pier. Because pier capacity is significantly affected by construction means and methods, the licensed design professional should understand these limitations. Construction methods described include excavation, casing, reinforcing steel installation, and concrete placement.Acceptance criteria and recommended procedures for construction, engineering, and evaluation are presented.