A respiratory mask assembly for delivering breathable gas to a patient includes a mask frame having a first cooperating interlocking structure; a mask cushion provided to the frame; a cushion clip to retain the mask cushion on the mask frame, the cushion clip having a second cooperating interlocking structure and being selectively attachable to and detachable from the mask frame, the first and second cooperating interlocking structures interlocking to secure the cushion clip on the mask frame; and an elbow joint provided to the frame and having a swivel tube adapted to connect to a gas delivery conduit. The first and second cooperating interlocking structures include a tab-recess arrangement in which a plurality of tabs are engageable within respective recesses.