The Department of Energy (DOE), led by the Office of Science's Fusion Energy Sciences (FES) program, has taken steps to facilitate fusion energy commercialization through public-private partnerships. These efforts represented about 1.2 percent (about $36 million) of FES's total funding obligations on average during fiscal years 2020 through 2023. The rest of FES's funding obligations (about 98.8 percent on average, or about $740.8 million) went to efforts to study, among other things, the science of plasma, collaborate internationally, and maintain facilities. DOE officials indicated that the relatively limited scale of investment in initiatives to facilitate commercialization largely reflects the immature state of fusion energy technology, which GAO reported on in March 2023. Another DOE entity—Advanced Research Projects Agency-Energy (ARPA-E)—obligated nearly $50 million in fiscal year 2020, and about $8.7 million on average during fiscal years 2021 through 2023 to fusion energy commercialization projects.