Despite increases in the human life span, people have not increased their rate of saving. In a phenomenon known as 'temporal discounting', people value immediate gains over future gains. According to a future self-continuity hypothesis, individuals perceive and treat the future self differently from the present self, and so might fail to save for their future. Neuroimaging offers a novel means of testing this hypothesis, since previous research indicates that self- vs other-judgments elicit activation in the rostral anterior cingulate (rACC). Using event-related functional magnetic resonance imaging, we predicted and found not only individual differences in rACC activation while rating the current vs future self, but also that individual differences in current vs future self activation predicted temporal discounting assessed behaviorally a week after scanning. In addition to supporting the future self-continuity hypothesis, these findings hold implications for significant financial decisions, such as choosing whether to save for the future or spend in the present.