The EXpedite the PRocessing of Experiments to Space Station, or EXPRESS Rack System, was developed to provide Space Station accommodations for small, sub-rack payloads. This paper describes the EXPRESS rack payload accommodations and interfaces to be provided on the International Space Station. The EXPRESS rack accepts both Shuttle middeck locker class and Standard Interface Rack (SIR) drawer class payloads. Payload capability includes existing experiments which have flown in the Shuttle middeck, Spacelab, and Spacehab, as well as new Space Station payloads and transition payloads from the Russian Mir. EXPRESS rack accommodations include structure, power, data, command and control, video, avionic air, water cooling, vacuum exhaust, and GN2. Standard hardware and software interfaces, and simple streamlined integration processes will make it much easier for researchers to integrate and fly their payloads on Space Station.