[en] The Facility for Rare Isotope Beams (FRIB) is a new nuclear science facility funded by the DOE Office of Science and Michigan State University (MSU). FRIB is currently under design and will be located on the MSU campus. The centerpiece of FRIB is a heavy ion linac utilizing superconducting RF cavities and magnets which in turn requires a large cryogenic system. The cryogenic system consists of a commercially produced helium refrigeration plant and an extensive distribution system. Superconducting components will operate at both 4.5 K and 2 K. This paper describes the conceptual design of the system including the expected heat loads and operating modes. The strategy for procuring a custom turnkey helium refrigeration plant from industry, an overview of the distribution system, the interface of the cryogenic system to the conventional facilities and the project schedule are also described.