A securement device for retaining medical tubing, catheters, and other medical fixtures proximal a patient's skin. The device has a base, at least one channel formed in the base, a flexible strap for overlying the base, and a coupling assembly for coupling the strap to the base. Embodiments for use with Foley catheters include a plurality of channels of differing diameters. Embodiments for use with a peripheral catheter include a single channel for retaining a spin nut. The coupling assembly includes left and right tracks in left and right sides of the base, and left and right rails on an underside of the flexible strap at left and right ends of a body of the strap. The left rail is removably coupled and held within the left track on the base, and the right rail is removably coupled and held within the right track on the base.
