A closure assembly is provided for a specimen collection container. The closure assembly includes a bottom ring and top ring assembly. The bottom ring is removably attachable to the open end of the container. The top ring assembly, which is removably attached to the bottom ring, includes a mounting ring and a pierceable, resealable septum that closes the bottom ring and permits pierceable instrument access therethrough. The container interior can also be accessed by the removal of the bottom ring from the open end of the container or by the removal of the top assembly from the bottom ring.