This paper estimates the impact of "compulsory volunteerism" for adolescents on subsequent volunteer behavior exploiting the introduction of a mandatory community service program for high school (HS) students in Ontario, Canada. We use difference-in-differences approach with a large longitudinal dataset. Our estimates show that the policy crowded out volunteering of those who were not directly affected by the policy. More importantly, we find no evidence that "compulsory volunteerism" increased altruism: while the policy increased volunteer participation during HS, those mandated by the policy volunteered less than they otherwise would have been expected to after HS completion.