Objective: Mobile technology has facilitated rapid growth in the use of intensive longitudinal methods (ILM), such as ecological momentary assessments (EMA), that help identify proximal indicators of risk in real-time and real-world settings. To realize the potential of ILM for advancing knowledge regarding suicidal and self-injurious thoughts and behaviors (SITB), this article aims to provide a systematic review of safety protocols in published ILM studies of youth SITB, highlight considerations for maximizing safety, and offer an agenda for future research. Method: We conducted a systematic review of risk management strategies in published studies applying ILM to assess SITB in youth. Results: The review indicated diverse safety strategies, with near-universal use of preventive strategies before beginning ILM surveys. Strategies for participant protection during the survey period included automated protective messages to seek support when elevated risk was detected; and staff-led strategies, some of which included active outreach to parents/caregivers when youth responses suggested elevated risk. Studies assessing suicidality all provided staff-led follow-up. There was minimal information on youth reactivity to intensive longitudinal assessments of SITB. Available evidence did not suggest increased suicidal ideation, suicide attempts, self-injurious behavior, or deaths with ILM. Conclusions: Based on the review, we propose a research agenda to inform safety procedures in ILM research and a model for managing risk in future ILM studies of youth SITB. This model begins with a needs assessment and proposes a “goodness of fit” approach for matching safety procedures to the specific needs of each ILM study.