Research is limited on the analysis of constructs such as coping, quality of life, and adjustment for African Americans. In psychosocial-oncology, adequate measures of these constructs are essential in order to establish comprehensive models of health and disparities. In this project, an Item Response Theory (IRT) approach to examining Differential Item Functioning (DIF) was conducted on the Cancer Behavior Inventory (CBI), a 33-item measure of self-efficacy for coping with cancer. DIF was tested across groups of African Americans (N = 245) and Whites (N = 407) with cancer. DIF was flagged for three items; however, these differences have low influence on the measure at the scale level. This project provides a modern methodological approach to validating health related constructs and allows for the interpretation of differences between the two groups as, not an artifact of DIF, but true difference.