Prior social movement research has focused on the role that axes of inequality - particularly race, class, gender, and lesbian, gay, bisexual, transgender, and queer (LGBTQ) status - play for who participates and how they do so. Age is another important axis of inequality. The pervasiveness of a youth deficit model, which casts young people as deficient and requiring benevolent adult tutelage, is of particular concern for youth. This chapter assesses whether the internalization of the deficit model influences young people’s activism and how they perceive their engagement. Drawing on interviews with 40 high school and college students from a southwestern US city, we find that many young people have internalized deficit-model assumptions, affecting when and how they participated. This was most evident among high school students, who limited their participation because they were “not old enough” or gravitated toward more “age-appropriate” forms of activism. Interestingly, we found college students were more willing to engage in online activism but also felt compelled to do significant research on issues before participating, thereby distancing themselves from the deficit model’s assumptions of their political naivety. Finally, some participants felt discouraged by the perceived ineffectiveness of protest, which resonated with deficit model narratives of the futility of youth engagement. These findings highlight the importance of understanding the impacts of an internalized deficit model as well as considering age as an axis of inequality in activism. Youth engagement is best supported by seeing young people as capable actors with unique interests, capacities, and points of view.