Background. Substance Use Disorder can impede parent–child relationships. The Theory of Ambiguous Loss provides a structure for occupational therapy practitioners in developing interventions to support the parent–child relationship. Purpose. This study explores the roles of parents of adult children diagnosed with Substance Use Disorder in the context of the Theory of Ambiguous Loss. Method. Volunteer participants were recruited from three urban parental support groups. Inclusion criteria were involved in a support group and having an adult child diagnosed with Substance Use Disorder. Eight mothers and one father participated in semi-structured interviews using a phenomenological approach. Themes and structural descriptions were developed. Findings. Five themes were identified: hopeful coping, occupational interference, changes in social constructs and participation, burdenful caregiving and receiving, and blending of occupations. Themes offer intervention considerations for occupational therapy. Implications. Research provides additional conceptual consideration to build occupation-centered interventions for parents and their adult children in Substance Use Disorder recovery.