text: The church's main sanctuary is adjacent to the lower plaza and is about  beneath the plaza. The sanctuary has movable pews that can seat up to 850 people. There was also a black-box theater, a library, kitchen, daycare center, clergy offices, dressing rooms, choir rooms, and lecture and community rooms. Upon the church's completion, there was a two-manual, two-pedal organ with 2,175 pipes. Inside the church is the 24-seat Chapel of the Good Shepherd (also known as the Nevelson Chapel), which was donated by parishioner Erol Beker and designed by sculptor Louise Nevelson. The basement theater was used by the York Theatre. St. Peter's Church also hosts a jazz ministry created by the Rev. John Garcia Gensel, who in 1965 became the Minister to the Jazz Community. The jazz ministry has sponsored several programs over the years, such as free jazz performances at the base of the office tower. The church has hosted memorials and funerals for jazz musicians such as Miles Davis, Dizzy Gillespie, and Thelonious Monk. In 2021, the church was seriously damaged after a broken water main flooded its space.
  Structural features
  The tower stories are of trussed-tube construction. Each of the tower stories measures , or  in total. Within the office stories, the elevator shafts and emergency stairs are embedded in a service core at the center of each story. The core is about , while the floor space around the core is just less than  wide. Overall, the Citigroup Center is made of  of steel, two-fifths of the amount used in the Empire State Building.
  Stilts
  The tower is supported by four stilts measuring approximately  high with a cross section of . The stilts are underneath the centers of each elevation of the facade, and the building's corners are cantilevered  outward from the core. According to Stanley Goldstein of LeMessurier's New York City office, stilts at the centers of each elevation would be able to withstand forces from "quartering winds" from the corners, compared to stilts at the corners. Additionally, the stilts allowed the building to have a smaller foundation than in a conventional building of similar size.