An infusion set (101) includes a base (111) and an inserter (121) removably connected to the base (111). A catheter (134) is movable from a first catheter position disposed substantially entirely within the inserter (121) to a second catheter position' in which a free end of the catheter (134) is disposed externally of the base (111). An introducer needle (142) is located within the catheter (134) and is movable with the catheter (134) between a first introducer needle position disposed substantially entirely within the inserter (121) and a second introducer needle position in which a free end of the introducer needle (142) is disposed externally of the base (111). A spring member (171) moves the catheter (134) from the first to the second catheter position and the introducer needle (142) from the first to the second introducer needle position to facilitate insertion of the catheter (134). The spring member (171) is disposed substantially entirely within the base (111) when the catheter (134) is in the second catheter position.
