An interface assembly includes an interface, such as a mask, that is secured to a head using a headgear assembly. The headgear assembly can include at least one halo portion and a plurality of straps. The headgear assembly can include both a front halo portion and a rear halo portion. In some arrangements, the headgear and mask define an adjustable closed loop. In some arrangements, the headgear can include one or more rigid portions that contact the user's face to at least partially isolate a seal of the mask from tightening forces applied to the headgear. In some arrangements, the mask is an oral-nasal mask and the headgear applies a force to the mask including an upward force component. In some arrangements, the headgear can be contoured to the user's head.