A developmental contextual test of a dual-cycle model of identity formation is presented. In addition to a commitment-formation cycle-represented by Marcia's (1966) classical dimensions of exploration in breadth and commitment making--the model comprises a commitment-evaluation cycle--constituted by 2 additional dimensions of exploration in depth and identification with commitment. In a sample of 402 college students assessed 4 times over 2 years, both dimensions of the commitment-formation cycle and exploration in depth increased across time. Identification with commitment showed a slight decrease across time. Latent growth curve (LGC) modeling analyses indicated that the 2 identity cycles are interwoven in a dynamic interplay that defines identity formation. Contextual influences on identity development were identified through a natural experiment. Commitment evaluation constituted the core identity cycle in the normative-progression group (i.e., students who moved on to the sophomore year). Both commitment formation and commitment evaluation were at work in the reorientation group (i.e., students who repeated their freshman year or changed their major). Implications and suggestions for future research are discussed.