Taking the ACT test is an important step in the college-going process. Over 1,500 colleges across the US educating approximately 1.5 million first-time degree-seeking undergraduates either require, recommend, or consider test scores as a criterion for admission decisions. The registration fees for taking the ACT on a national test date--at $55 for the ACT without writing and $70 for the ACT with writing for the 2020-21 school year--can be a financial burden for students from low-income families, thus potentially limiting their access to many colleges across the US. To remove this financial burden and enable test-taking as well as increased subsequent college attendance among students from low-income families, ACT provides eligible students with fee waivers to use when registering for the ACT. These fee waivers include free access to ACT online test prep products, free additional score reports to send to colleges, and college application fee waivers that ACT encourages colleges and universities to accept. As the first brief in a series of studies investigating ACT's fee waiver program, this report provides an overview of the number and percentage of ACT® national test date registrations that were completed with a fee waiver between the 2014-15 and 2018-19 school years. In this first brief, the focus is on ACT registrations that were completed using fee waivers and not on the individual students who used the fee waivers to register. The focus is on registrations because students could register to take the ACT on more than one test date and because students who were eligible for fee waivers could use up to two fee waivers to register for the ACT. Given this focus on registrations, the results include students who may have registered and tested multiple times in this five-year window.