In this study we developed a short version of the Individuation Test for Emerging Adults (ITEA-S) and tested its measurement invariance across Slovene and U.S. samples of emerging adults. The item reduction process resulted in retaining 21 out of 36 items. The content analysis of the retained and discarded items revealed that the ITEA-S adequately measures the 5 individuation domains (support seeking, connectedness, intrusiveness, self-reliance, and fear of disappointing the parent). In our samples, the ITEA-S demonstrated evidence for construct validity and its 5 scales showed adequate internal consistency. The scale scores were also meaningfully associated with the relevant demographic variables in both countries, as well as the three scales of the Psychological Separation Inventory (Hoffman, 1984 ; the Slovene sample), and the scales of the Differentiation of Self-Revised questionnaire (Skowron & Schmitt, 2003 ; the U.S. sample). The results of multiple group confirmatory factor analyses supported the hypothesis of full metric and partial scalar invariance for both ITEA-S forms (in relation to mother and father) across the 2 country groups.