The present research tested the idea that a self-determined orientation may help people manage death-related thoughts and anxieties, and mitigate the effects of death awareness on well-being. Seven studies (N = 3,331), using a diversity of measures and manipulations, were consistent with that idea. First, mortality salience (vs. other topic primes) increased death-thought accessibility, but not if participants had high need-satisfaction (Study 1, n = 160; Study 2, n = 216) or were prompted to recall self-determined experiences (Study 3, n = 188). Second, need-satisfaction was associated with reduced death anxiety (Study 4a, n = 301; Study 4b, n = 1,848), and priming self-determined concepts eliminated the effect of mortality salience on death anxiety (Study 5, n = 119). Third, heightened death-thought accessibility was related to lower satisfaction with life (Study 6, n = 271) and happiness (Study 7, n = 228), but not among those with high need-satisfaction. Supplemental analyses suggested the effects of need-satisfaction were not due to associations with affect (Studies 1, 6, 7), epistemic certainty (ideological dogmatism, Study 4a), or mindfulness (Studies 5b and 6); need-satisfaction mitigated the effects of existential concern via self-esteem but not via growth orientation (Study 4b) nor due to its relationship with Openness (Studies 6 and 7). Together, these findings suggest a self-determined orientation can help buffer existential concern and buoy well-being and point to a potential existential protective function beyond its known growth-oriented functions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).