This study outlines the development and validation of a new 4-dimensional job insecurity measure (JIM). Items were generated from interviews with Australian employees facing an objective threat of job loss. The measure was then validated on a North American sample of 1,004 respondents. Exploratory and confirmatory factor analyses (EFA and CFA) with tests of sample invariance supported an 18-item measurement model consisting of 4 correlated but distinct subscales of insecurity: Job Loss, Job Changes, Marginalization, and Organizational Survival. The results indicate convergent and discriminant validity as well as high internal consistency for the instrument. Significant associations with psychological well-being (job related affective well-being, job satisfaction) and organizational attitudes (organizational commitment, trust in management, intention to resign) established the criterion-related validity of each subscale. These findings support the use of the instrument in academic and applied settings.