Reintegration of ex-combatants and persons formerly associated with armed forces and groups is the process through which they transition sustainably to live as civilian members of society in communities of their choice. The context in which reintegration takes place, the specific challenges, and opportunities, as well as the characteristics and background of those involved, could differ considerably. Depending on the circumstances, these reintegration processes may be supported in a variety of ways and at different levels – and at the same time. Most often, formal reintegration support is provided to individuals, based on an agreed eligibility to participate in a reintegration programme. However, it is increasingly argued that support to reintegration is most effective if community based. This Guidance Note on Supporting Community-Based Reintegration of Former Members of Armed Forces and Groups will assist in designing, negotiating and managing support to reintegration processes. In fact, all reintegration processes are community-based, since one of the major aspects of reintegration is to reconnect as a civilian with the community and to play a constructive role in social life. The essence of community-based reintegration (CBR) support is then to assist and empower communities to ‘absorb’ the women, men, girls, and boys exiting armed forces and groups – socially as well as economically. The Guidance Note is complementary to the current UN Integrated Disarmament, Demobilization and Reintegration Standards (IDDRS) and the 2018 Addenda to the 2015 Madrid Guiding Principles in the context of armed groups designated as terrorist organizations. This Guidance Note identifies various possible ways to support communities in increasing their ability to welcome and absorb former members of armed forces and groups. It also helps in creating an awareness of a number of dilemmas and risks involved in external support to CBR. It would for example help preventing harm to (potential and spontaneously ongoing) reintegration processes. And, importantly, the Guidance Note also assists in finding in specific settings the most appropriate balance between the provision of community-based and individual reintegration support. Providing support through the community could indeed mitigate possible negative perceptions in the community that ex-combatants are being rewarded through targeted individual reintegration benefits.