A luer for a catheter is disclosed. The luer has a proximal luer housing having a proximal opening, a distal luer housing having a stem and a distal opening, and a threaded element disposed on an external surface of the luer. The proximal housing and the distal housing define a fluid channel, and the proximal housing is slidably attached to the distal housing so that in a closed configuration the proximal opening is fluidly sealed by the stem, and in an open configuration the fluid channel is in fluid communication with the proximal opening. The luer can be formed integral to a catheter hub.