AbstractINTRODUCTION A shared identity is associated with effective teamwork. Therefore, interprofessional identity is likely to be associated with interprofessional collaboration. However, interprofessional identity has hardly been investigated. National but also cross-cultural research on interprofessional identity can be enabled when such a construct can be measured in several countries. One psychological theory, extended professional identity theory (EPIT), describes interprofessional identity as an identification with a wider circle of group membership. Recently, an interprofessional identity measure was published based on EPIT, extended professional identity scale (EPIS). The purpose of this study is to find additional evidence for EPIT by developing a Lithuanian version of EPIS (EPIS-LT) and to confirm its construct validity. In addition, to explore whether interprofessional identities are similar across different disciplines. METHODS Face and content validity were confirmed through the translation process. A confirmatory factor analysis (CFA) was conducted with 554 responses of students and practitioners of eight disciplines. Differences were analyzed with ANOVA. RESULTS Value of all goodness-of-fit indexes met their standard. Factor loadings of CFA ranged from 0.49 to 0.61. Internal consistency of subscales was 0.76, 0.79 and 0.84 respectively and the overall scale 0.87 (95% confidence interval: 0.86, 0.89). Interprofessional identities did not differ between disciplines with exception of pharmacy and dietetics. DISCUSSION Findings provide additional evidence for EPIT. The EPIS-LT is a reliable and valid instrument similar to the original EPIS. Interprofessional identity can differ between disciplines. Additional research across different countries can reveal whether this is the same in other countries.