The transition from high school to postsecondary education is one of the most important points in a student's educational journey. Yet, as students attempt to navigate the many steps involved in accessing postsecondary education, it is also a juncture where students are most at risk of falling off track. The responses to the COVID-19 pandemic -- including school closures, social distancing guidelines and stay-at-home orders -- have made this transition point even more fraught. One major question for students in the midst of this transition revolves around affordability: Will they be able to receive the financial support that enables them to pay for tuition, fees and other living expenses associated with being a postsecondary student? In order for students to receive the information that will allow them to answer that question, they must take a key step: filling out the Free Application for Federal Student Aid. Filling out the FAFSA allows students to learn whether they are eligible to receive federal financial aid; many states use the FAFSA to determine student eligibility for state financial aid programs as well. Currently, far too few students are taking this crucial step; researchers estimate students are missing out on $24 billion in federal and state grants, subsidized loans and work-study funding each year because they are eligible for aid but do not complete the FAFSA. This Policy Brief is one of six dedicated to various facets of the transition from secondary to postsecondary education, now complicated by the COVID-19 pandemic. It focuses on the populations already underserved in our nation's education system. The series -- which builds upon "A State Policymaker's Guide to Equitable Transitions in the COVID-19 Era" (see ED606369) -- provides actionable steps and examples for state policymakers to consider as they address the transition from high school to college and the workforce.