The Self-Determination Inventory: Student Report (SDI: SR) was developed to measure the self-determination of adolescents and was recently validated for students aged 13-22 with and without disabilities across diverse racial/ethnic backgrounds. The SDI: SR is aligned Causal Agency Theory and its theoretical conceptualizations of self-determined action. The validation of the SDI: SR was undertaken in two forms--online, computer-based and paper-and-pencil. The present study examined overall self-determination scores of student participants (with and without disabilities) who took the SDI: SR via the online and paper-and-pencil format to inform future research and practice using the SDI: SR. Findings suggest that the same set of items can be utilized across administration formats, but that there appear to be differences in overall SDI: SR scores when online and paper-and-pencil formats are utilized although these differences are not influenced by disability status. Implications for future research and practice are discussed to provide direction to the field related to assessment development and use of the SDI: SR in educational contexts.