Background. The aim of this study is to analyse the determinants of the occurrence of qualitative and quantitative job insecurity. It focuses on three career variables (employability, career exploration, and career uncertainty) and the way they contribute to individual reactions (defined as financial and social strain) to job insecurity. In addition, it takes into account the contextual factors, such as sector and organizational change in explaining how job insecurity is perceived and responded to." "Methods. An online survey was carried out in a sample of 205 respondents employed in various Lithuanian rganizations. They filled out a questionnaire which included measures of job insecurity, career attitudes, and financial/social strain. The data were analysed in the full sample, as well as in four subsamples that were split regarding two parameters (public vs. private sector; no recent organizational change reported vs. recent Organizational change reported). Results and conclusion. The hierarchical regression analysis showed job Insecurity to be strongly related to financial and social strain. However, it draws a slight distinction between qualitative and quantitative job insecurity as predictors of strain. Furthermore, a moderator analysis has revealed several moderating effects of career variables in the relationship between job insecurity and financial/social strain. Finally, it was found that organizational change and type of sector may play a role in determining the interplay between career factors, job insecurity and strain, as job insecurity effects were quite different across different subsamples. To generalize, this study emphasizes the importance of understanding how personal variables, such as career attitudes and beliefs, might change the subjective experience of job insecurity in objectively different contexts.