The Free Application for Federal Student Aid (FAFSA) is an important tool to help students find financial assistance. Not only do students fill out the FAFSA to apply for federal aid for postsecondary education, but also to be considered for aid by states, institutions, and private funders. A report from the National Center for Education Statistics (NCES) indicates why some students fail to apply.
The report can be obtained at https://nces.ed.gov/pubs2018/2018061.pdf.