A stabilizer (10) is provided for a patient interface (16). The patient interface (16) includes a frame (17). The stabilizer (10) is movable between a first position with respect to the frame (17) and a second position with respect to the frame (17). The stabilizer (10) includes a biasing mechanism (42) that biases the stabilizer (10) into the second position. A method of fitting a patient interface (16) to a patient's face is provided. The patience interface (16) includes a frame (17), a cushion (19) attached to the frame (17), a stabilizer (10) supported by the frame (17) for movement with respect to the frame (17), a biasing mechanism (42) that biases the stabilizer (10) with respect to the frame (17), and a lock mechanism that locks the stabilizer (10) at a position relative to the frame (17) against the bias of the biasing mechanism (42). The method includes placing the cushion against the patient's face to establish a substantially airtight seal at a first comfortable position； unlocking the lock mechanism to permit the biasing mechanism to bias the stabilizer against the patient's face when the cushion is in the first comfortable position； and locking the lock mechanism to lock the stabilizer and stabilize the cushion at the first comfortable position.
