Improving risk prediction of Alzheimer’s dementia poses challenges to healthcare professionals, patients, and their social environment. Moreover, predictive diagnosis faces limited operationalized clinical recommendations. In this study, we developed manuals for counseling individuals with mild cognitive impairment on their biomarker-based dementia risk prediction; we interviewed 16 participants postcounseling. The interview analysis examines sources of knowledge concerning the decision regarding risk prediction. Subsequently, an interdisciplinary interpretation discusses implications for practice. By focusing on sources of the participants’ knowledge, we identified epistemic authorities, such as (former) medical-related professional background or previous disease experiences. The findings provide information on cues and conversational elements for improving counseling sessions. Sensibly integrated language-based and legal considerations may achieve a targeted and efficient joint decision-making process.