Abstract: An adjustable door frame system includes at least one vertical frame member having a movable vertical subjamb assembly capable of outward movement relative the vertical frame member. The adjustable door frame system also contains a horizontal frame member having a movable horizontal subjamb assembly capable of outward movement relative the horizontal frame member. The door frame system also contains a plurality of adjusting mechanisms coupling the vertical subjamb assembly and horizontal subjamb assembly to the frame members. Each adjusting mechanism includes a hex nut connected to its subjamb assembly with a hex nut clip, and a hollow set screw and guide tube. Rotation of the hollow set screw causes the hex nut to move axially along the guide tube thereby causing the hex nut clip and its connected subjamb assembly to be adjusted outwardly with respect to the door frame system, thereby filling a gap between its frame member and the wall section.