An implantable connector assembly (14) for communicating an element to an implantable device (12) within a patient (20) comprises a plug (16), a receptacle (18), and a pair of communication structures (72, 108). The plug (16) includes a plunger body (64). The receptacle (18) includes a sleeve (98) and a stopper (114). The sleeve (98) defines an opening (104), and the stopper (114) is resiliency mounted within the sleeve (98) to cover and fluidly seal the opening (104). The pair of communication structures (72, 108) is positioned respectively on the plunger body (64) and the sleeve (98). One of the communication structures (72, 108) connects to a source and the other communication structure (108, 72) connects to the implantable device (12). The plunger body (64) inserts into the sleeve (98) to displace the stopper (114) and couple the pair of communication structures (72, 108) for communication of the element therebetween.