The Peace Treaty between the Revolutionary Armed Forces of Colombia (FARC) and the Colombian government in 2016 was a breakthrough toward ending an armed conflict of more than six decades. One requirement for its success is the reintegration of former combatants of the FARC into society, which in this case has been designed as a collective reintegration process. We conducted a qualitative field study with 20 former combatants of the FARC to understand their perception of this reintegration process using the framework of social identity theory. We found a strong disparity between the desire of participants to adhere to their identity as FARC while coming to terms with its decreasing likelihood. Participants felt threatened in their identity as FARC due to the violence targeted at them, their stigmatization and rejection by society, the perceived noncompliance of the Colombian government, and the increasing disintegration of the FARC. We discuss how identification with the FARC leads to different avenues of reintegration and affects former combatants' relations with society and the Colombian government. Adding to a multidimensional analysis and implementation of peace building, we highlight the need for structured reintegration programs that consider the psychosocial needs of all parties involved.