Abstract To address counselors' need for a reliable measure of career adapting thoughts and behaviors as well as researchers' need for a specific measure of adapting as a dimension in the model of career adaptation, we developed the Student Career Construction Inventory (SCCI). In the study, 486 high school students (55% female), 290 college students (59% female), and 220 graduate students (82% female) responded to the SCCI. The SCCI contains 18 items across four scales assessing: (a) Crystallizing a vocational self-concept, (b) Exploring to gather information about occupations, (c) Deciding to commit to an occupational choice, and (d) Preparing to implement that choice. The four scales interrelate to constitute a continuum reflecting the general factor of adapting responses during the exploration stage of a career. Each scale assesses a specific group factor reflecting a particular career construction task involving crystallizing, exploring, deciding, and preparing. The results of a confirmatory factor analysis indicated that the SCCI displays configural and measurement invariance, meaning that its factor structure is replicable and generalizable across high school, college, and graduate students. The SCCI did not show scalar invariance because, as expected, the mean scores for the scales were elevated for older and more educated participants. The SCCI, as a measure of adapting responses, correlated as predicted with concurrent measures of three criteria: adaptive readiness, adaptability resources, and adaptation results. A provisional test of the career construction adaptation model indicated that, as hypothesized, adapting behaviors mediate the relationship between adaptability resources and adaptation outcomes.