Abstract: I have invented an apparatus for creating an adjustable foundation, for residential and light commercial structures, that are supported on concrete drilled piers or concrete pad footing supports. The apparatus is an adjustable pier/footing cap, added to conventional drilled piers/footings at the time of foundation construction; said drilled piers are commonly used to support a building foundation in expansive soil areas and/or in other areas where upper bearing soils are weak or incompetent. The adjustable pier/footing caps are partially imbedded in the concrete drilled piers/footings when the piers/footings are poured and then into the foundation walls of the building when said foundation walls are poured. Upon settling or upheaval of the foundation, the adjustable pier/footing caps can be adjusted to lower or raise the building without replacing the drilled pier/footing with an expensive remedial piering device, and without substantial excavation around the foundation.