Adaptive medical article securement devices are described. These devices retain a medical article, for example, a catheter hub or a connector fitting, in position on a patient's body and reduce or inhibit longitudinal or other movement of the medical article. The securement device includes an adaptive retainer and at least one anchor pad used to attach the securement device to a patient's skin. The adaptive retainer is a flexible element that can adapt and conform to an exterior portion of the medical article to be secured, and in doing so forms a central channel in which at least a portion of the medical article becomes disposed. In some embodiments the retainer includes at least one engaging element that can engage a retention element disposed on the medical article. The engaging element, alone or in conjunction with the retention element and/or the shape (e.g., tapering) of the central channel, reduces or inhibits longitudinal motion of the medical article in the central channel.