Recent research on the generations in the workplace has acknowledged the role organizations play in creating generations and the stereotypes associated with them. However, how these stereotypes are formed has yet to be empirically explored. This paper analyzes the stereotypes associated with Millennials based on an in-depth case study of a population of drivers in a French railway company. This shows that these stereotypes mostly reflect the transformation of professional and organizational identities. The “elders” differentiate themselves from the new organizational generation to enhance the appearance of their skills, knowledge, and values, thus maintaining a balance of power that is favorable to them. Stereotypes also represent generational imprints that work as time markers in shaping the collective memory of their profession. By exploring the relationship among organizational changes, organizational generations, and generational stereotypes, this research produces a more complete understanding of the generational phenomenon in the workplace.