Multiple Alzheimer's disease (AD) secondary prevention trials are currently underway to evaluate promising therapies. Trial eligibility often requires prospective participants to be cognitively unimpaired, learn something about their AD risk, and enroll with a study partner. Little is known about how individuals make enrollment decisions, such as their motivations, perceptions of risk, and reactions to being ineligible. Moreover, it is unknown how they select study partners and how, if at all, they include study partners in enrollment decisions. Data are collected as part of the Study of Knowledge and Reactions to ApoE Testing (SOKRATES 2). SOKRATES 2 participants are cognitively unimpaired adults aged 60–75 who learned their Apolipoprotein E (ApoE) genotype as part of screening and eligibility for the Alzheimer's Prevention Initiative's Generation Program trials, which are testing treatments to prevent the onset of cognitive and functional declines related to AD in individuals at increased genetic risk. The sample was recruited to be balanced on age, gender, and ApoE genotype. Interviews were conducted with 70 individuals following ApoE disclosure. Initial interviews were conducted 3 months post-disclosure. Follow-up interviews—conducted 12-months after the initial interview—are currently underway. The follow-up structured interview guide includes questions about study partner selection and trial-related decision making. All interviews are being recorded, transcribed, and analyzed in NVivo 12.0. The University of Pennsylvania IRB approved this study. Results show that the majority of individuals reached the decision to participate alone and did not engage others, including their potential study partner, in trial-related decision-making. Common reasons for participating include desire for personal medical benefit, AD family history, and advancing science for others’ benefit. Although there are risks associated with the Generation Studies’ experimental treatments and procedures, participants did not consider participation particularly risky. Individuals ultimately ineligible to participate reported experiencing disappointment and, in some instances, resentment and anger. Understanding how individuals decide whether or not to participate in AD secondary prevention trials, whom they engage in trial-related decision making, and how they feel if they are not eligible is important for designing recruitment and engagement strategies.