Abstract: A patient transfer device including a retractable wheel assembly, a caster brake and a track extension is provided. The retractable wheel assembly can include a cammed linkage arm operatively coupled to a retractable wheel. As the patient transfer device moves downwardly over a step, the cammed linkage arm can bear against the step, rotating the retractable wheel to a stowed position. The caster brake and the track extension can cooperate to stabilize the patient transfer device at the top and bottom of a stairway, respectively. The caster brake and the track extension can each include a high-friction engagement surface that is vertically offset from the respective caster and track. The retractable wheel assembly, caster brake and track extension can improve the control the patient transfer device along level, ramped and stepped surfaces, particularly for operators lacking sufficient training or experience.