Outstanding federal student loan debt exceeds $1.6 trillion and is owed by about 45 million borrowers. Since taking office, the Biden Administration has taken various actions to address student loan debt. These actions have ranged in scope (both in terms of borrower populations affected and associated modification costs), rationales, and the avenues through which they were taken (e.g., formal rulemaking procedures, issuance of guidance). A primary criticism of many of the actions the Biden Administration has taken relate to these actions' costs to the federal government. In contrast, supporters contend that these actions help address borrower difficulty in managing and repaying student loan debt. This report compiles executive actions taken during the Biden Administration that have affected the costs of outstanding federal student loans. It begins by briefly describing relevant federal student loan programs. It then explains the methodology CRS used to compile the list of executive actions. Next, the report discusses accounting for the costs of federal student loan programs, including discussion of the Federal Credit Reform Act of 1990 (FCRA) because CRS's methodology relies on how the U.S. Department of Education (ED) accounts for the costs of the student loan programs under this act. Finally, the report lists and describes executive actions taken in FY2021-FY2023 that ED recognized as affecting the cost of outstanding federal student loans and provides ED's cost estimate for each action. Table 1 summarizes each of these actions and their modification costs. Table 2 presents net modification costs for the relevant federal student loan programs for FY2021-FY2023.