The expansion of immigration detention in the United States has been attributed to policy, privatization, and anti-immigrant racialization. This research extends understandings of immigration detention's growth by focusing on how Immigration and Customs Enforcement (ICE) maintains the necessary space to detain migrants during this expansion. In this article, I introduce the concept of “malleable detention:” the flexible strategies and methods used to restructure space within immigration detention. I base this concept on findings from an analysis of the T. Don Hutto Detention Center - a detention site that has remained open despite various abuses, protests, and closures. Using statements from ICE officials, intergovernmental service agreements (IGSAs) between ICE and local governments, government reports, nongovernmental reports, and newspaper accounts, I find that the Hutto site displayed three forms of malleable detention. Detention was made malleable through repurposing non-detention space into detention space, maintaining flexibility in the detained populations, and reconfiguring contracts that helped keep detention open. Beyond the Hutto case, the malleable detention concept extends to detention sites throughout the U.S. This provides evidence into how ICE is able to sustain enough detention space that makes the U.S. the largest detainer of immigrants in the world.