Negative symptoms and cognitive dysfunction are two symptomatic categories of schizophrenia spectrum disorders (SSDs) that significantly impair functioning. Treatment for adults with SSDs continues to focus primarily on medication adherence and positive symptom reduction, despite the fact that medication has little impact on negative and cognitive symptoms within this population and, thus, little impact on improving community functioning. This two-part series presents an intervention developed to increase community participation in adults with SSDs. This article presents a comprehensive description of the functional impairments experienced by this population, framed within the World Health Organization’s International Classification of Functioning, Disability, and Health. This article will also apply Self-Determination Theory to this population of adults with SSDs as a foundation to help this population increase community participation and successful integration.