This paper presents a summary-level comparison of the similarities and differences of tank closure programs at the four primary radioactive waste tank sites in the US Department of Energy (DOE) complex. The sites are Hanford, Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge Reservation (ORR), and the Savannah River Site (SRS). The depth of our understanding of the closure programs varies with the amount of detailed information each of the four sites has provided to date. This paper was prepared using the best available information, including direct communications with key tank closure personnel at each of the sites. Many of the current schedules are under review for possible acceleration.