A catheter securement device holds a medical article such as a catheter in position upon the body of a patient and at least inhibits longitudinal movement of the medical article. The securement device includes a retainer and a clamp. The retainer and clamp include interengaging structure. The interengaging structure may be a ratchet mechanism by which a medical provider tightens the clamp against the retainer. The ratchet mechanism allows a single securement system to be used with medical articles that have different longitudinal lengths as well as medical articles that have distally located contact surfaces. The retainer forms a channel into which at least a portion of the medical article is inserted. Each of the retainer and the clamp include at least one abutment surface that can abut against a contact point or surface on the medical article. The abutments inhibit motion of the medical article in proximal and distal directions through the channel when the clamp is tightened against the retainer. The securement system may be designed for single or multi-use.