How does the provision of public pension benefits impact private savings? We answer this question in the context of a Danish reform that increased social security eligibility ages. Using administrative data and a regression discontinuity design, we identify the causal effects of the policy on savings throughout the financial portfolio. We find increases in contributions to personal and employer-sponsored retirement accounts when delayed benefit eligibility induces extended employment. We argue that inertia—the continuation of previous savings behaviors—is a key mechanism, and we highlight how firm default contribution rate policies can mediate savings responses to social security reform. (JEL G51, H55, J22, J26, J32)