Academic incivility can create divisiveness and affect learners' sustainability towards degree attainment. Therefore, there is a need to empirically assess learner views on what constitutes academic incivility in higher education. To fill this gap, we developed the "Incivility Indicators Instrument" (i[superscript 3]), a multifaceted scale that measures the extent to which students view cumulative behaviors and dynamics as instances of academic incivility. To examine the reliability and factor structure of the i[superscript 3], we conducted a two-part study with two samples of adults in the United States who were enrolled in higher education programs. In study 1 (N = 342), we conducted an exploratory factor analysis (EFA) and found the initial three-factor structure. In study 2, we administered the instrument to a validating sample (N = 510) and examined the stability of the three-factor model and scores through confirmatory factor analysis (CFA). In this study, we describe the results of the study, provide implications, and discuss future directions.