A medical device securement system is configured to secure medical devices such as catheters in place. The securement system includes an anchor pad that attaches to a patient's skin. A malleable support base is attached to an upper surface of the anchor pad. The support base has front and back inclined surfaces that are separated by an offset surface that extends generally normal to both of the inclined surfaces. A spot of adhesive is applied to one or more of the inclined surfaces. A catheter assembly includes a connector having a first connector portion with a diameter larger than an adjacent second structure. The catheter assembly is attached to the support base with the first connector portion engaged with and supported by the back inclined surface, and the second connector portion engaged with and supported by the front inclined surface.