Methods and devices for fluid delivery and analyte sensing via an implantable port are disclosed where a port apparatus may be configured for placement within a body of a subject and may generally comprise a port housing and a catheter defining a first lumen which is fluidly coupled to the port housing. A flushing lumen may extend from the port housing and terminate at or near a distal tip of the catheter and an access port may be positioned within or upon the port housing and in fluid communication with the first lumen. Furthermore, an access device configured for percutaneous advancement into contact with the access port may also be included.