The insider threat is, at its core, a human problem that results from a complex interaction among individual and environmental factors. The social and behavioral sciences (SBS) are well-suited to address this complicated and persistent human problem. In 2016, the Office of the Under Secretary of Defense for Intelligence partnered with the Defense Personnel and Security Research Center to design a comprehensive research plan and strategy to integrate the SBS into the DoD counter-insider threat mission space. Developed in collaboration with subject matter experts (SME) and approved by the DoD Insider Threat Program Director, this strategic plan has three goals: 1) Align SBS with DoD’s counter-insider threat mission to ensure that the enterprise is well-equipped, trained, and vigilant in protecting DoD resources, personnel, installations, and equities; 2) Present a plan to drive current and future investment in SBS research; and 3) Communicate the SBS vision to senior leadership, stakeholders, and potential partners. The SME interviews resulted in five SBS Research Campaigns that together comprise the SBS Research Plan to counter malicious insider threat behavior: Employee Reporting; Technology, Tools & Data; Individual Factors; Organizational Factors; and Program Evaluation. As part of the interviews, SMEs also explained what is required for researchers to continue forward progress and execute the SBS Research Plan. Several SMEs drew on their own experiences building successful Insider Threat Programs, especially under adverse fiscal and cultural conditions. The two most commonly mentioned SME strategies for success—Tailor the Message and Build Strategic Partnerships—provide valuable lessons for SBS researchers who want to make a meaningful contribution to insider threat detection, prevention, and mitigation efforts.