Abstract: A needleless access port is assembled from parts sealed to a flexible container, such as a container for intravenous infusion, parenteral nutrition or transfusion. The port includes a lower housing for sealing to the container, the lower housing having an upright tower for mounting an upper housing. The upper housing has at least one connector or valve and a sleeve for mounting to the tower. The sleeve includes connectors so the upper housing can be mounted in a first, upper resting position, and a second lower, active position, for adding liquid to the container or for removing liquid from the container. Even after assembly to a container, the upper housing may be removed and the lower housing may be used instead with a standard IV spike set.