Abstract: An adjustable bracket for mounting a jamb to an adjacent framing member. The mounting assembly comprises at least one L-shaped member, an inner leg of which is secured to the back of the jamb. The outer leg of the member can be nailed to the surrounding framing to locate and support the jamb.In one embodiment, a pair of telescoping L-shaped members are provided, one of which is secured to the jamb while the other slides within it. The members are advantageously formed with stiffening means at the apexes, and can be formed with detents for engaging the opposite edges of a hollow molding strip.In another embodiment, the brackets engage one side of the molding strip, the other side thereof being forced into a slot extending along the door jamb. A retainer is described which aids in retaining the molding lip in the jamb slot.