Abstract: A window or door assembly including a jamb member and a jamb liner having a fastener opening coupled along the jamb member. A sash is moveably coupled along the jamb liner. The window or door assembly includes a structural filler coupled over a portion of the jamb liner, and the structural filler substantially conceals the fastener opening. The structural filler includes a flange sized and shaped to engage with the sash, and the flange substantially prevents movement of the sash over the structural filler. In one option, the flange extends along the structural filler and the sash. The structural filler further includes a contact surface engaged with the jamb liner and a projection rotatably coupled with the jamb liner, and the structural filler rotates in a first direction around the projection.