Naturally occurring social support relationships are a subtype of informal social support. Naturally occurring relationships may include parents, siblings, intimate partners, or friends. These relationships develop in the course of an individual's life; whereas, formal social support is received from structured services and interactions with medical doctors, nurses, counselors, educators, or clinicians. A review of the relevant literature found that few published programs give priority to incorporating social-support providers into the treatment program model for former prisoners with substance-use disorders. Of the few programs that include a focus on social support, even fewer use naturally occurring support. The program model proposed by the authors of this paper gives priority to the appropriate matching of a client's social support needs with formal and existing naturally occurring positive social support that reinforces emotions, cognitions, and behaviors that promote successful adaptive outcomes. When there is a limited or no positive existing social network, efforts must be made by program staff to assist the client in building a positive social network and increasing the skills needed to recognize and access needed positive social support. When there is a poor match of support needs and available support resources, efforts must also focus on building the skills of naturally occurring social-support resources in becoming actively involved in interventions. The authors describe "Support Matters," a naturally occurring social support program currently in the pilot test phase. It illustrates how social support interventions can be used to increase involvement in relationships that provide positive social support. 1 table, 1 figure, and 71 references