The Department of Homeland Security (DHS) has a vital mission: to secure the nation from the many threats it faces. The DHS vision is to ensure a homeland that is safe, secure, and resilient against terrorism and other hazards. These overarching goals are the basis for the IT mission and IT vision set forth in this document; the strategies and actions of the DHS CIO community are rooted in and aligned with the founding principles and highest priorities of Homeland Security. The DHS IT Strategic Plan 2015-2018 reflects our rapidly-changing IT environment and evolving mission and business needs, as well as IT's role in every aspect of security and resilience. It outlines DHS' IT priorities and provides strategic direction for the use of IT resources, in order to improve the efficiency of our programs, enhance our mission effectiveness, and ultimately, provide for the security of the American people. As part of its strategic planning process, DHS cross-Component leadership developed five high-level goals, each with no more than four achievable objectives. In addition, each goal and its objectives were given an outcome; that is, the intended end state once the goal and objectives are complete. The IT Strategic Plan collectively supports the strategies outlined in the Department's Strategic Plan for fiscal years 2012-2016 and the mission, goals, and objectives outlined in the 2014 Quadrennial Homeland Security Review (QHSR). It is an update to the DHS Information Technology Strategic Plan for fiscal years 2011-2015. The execution of the strategies in this plan is to be carried out under the leadership of the DHS CIO Council.