A catheter insertion device (10) is provided for positioning and inserting a catheter (14), particularly a midline catheter into a patient. The insertion device (10) includes an introducer needle (18) that extends from the distal end of the catheter during insertion. A manually operated actuator assembly (20) is movable with respect to a housing for deploying the catheter (14) over the distal end of the introducer needle (18). A step-wise movement of the actuator (20) advances the catheter (14) in stages over the introducer needle (18). A shuttling or indexing mechanism (60, 76) advances the catheter and prevents retraction of the catheter once deployed.
