This Identification of Best Practices in Peer Support Programs: White Paper seeks to identify elements associated with success in peer support program models as they might relate to the active-duty military and veteran environments. Peer support is assistance provided by a person who shares commonalities with the target population, for example, direct experience in a particular situation or event, familiarity with a particular stress or, or other shared characteristics. Currently, peer support is widely used in formal and informal programs and has been found to have a positive impact on individuals with shared diseases, conditions or situations. Potential positive outcomes from the use of peer support are listed in Figure 1. For the purposes of this paper, the primary population under consideration is active-duty service members, with the understanding that within that population there are many subset cultures and needs. Veteran populations are another critical group that could benefit from peer support programs, especially when separation from service distances an individual from the natural peer environment.