Using subscales of the Adult Needs and Strengths Assessment (ANSA) and an author created Crisis Event measure, holistic client functioning was assessed for persons diagnosed with comorbid serious mental illness (SMI) and primary healthcare diseases. An ex post facto, quasi-experimental, pre- and post-test design was selected to compare the effectiveness of an integrated behavioral and primary healthcare (IBPH) treatment approach to a treatment-as-usual (TAU) approach, across a 12-month treatment period.