More than a million federal student loan borrowers default each year, and the U.S. Department of Education reports that as of June 2020, roughly 1 in 5 borrowers with federal student loans was in default. Since that time, the coronavirus pandemic and related economic downturn have continued to take a significant toll on households and businesses across the country. Failing to repay a student loan can have serious, long-term financial consequences. When borrowers do not make payments, they become delinquent on their loans, and when they reach 270 days past due, they default. As a result, borrowers can face collection fees; wage garnishment; money being withheld from income tax refunds, Social Security, and other federal payments; damage to their credit scores; and even ineligibility for other aid programs, such as help with homeownership. This issue brief examines research on how borrowers perceive and behave within the student loan repayment system, and highlights key findings that could reduce rates of delinquency and default: (1) Effective communication can increase borrower engagement; and (2) Reducing friction points can improve enrollment in affordable repayment plans.