The burden of depressive symptoms among older Americans over the period 1992-2018 that is attributable to involuntary job loss, and the extent to which intervening on various mechanisms could mitigate it, have not been estimated. The long-term goal is to identify key mechanisms (e.g., loss of health insurance, unemployment, inadequate reemployment, financial hardship, etc.) that affect depressive symptoms over time in older Americans after job loss, in order to guide policy and interventions. As the first step toward this long-term goal, the objective of this application is to quantify the burden of depressive symptoms among older Americans that is attributable to job loss, adjusting for time-varying confounding, and to evaluate time to reemployment as one mechanism. The central hypothesis is that involuntary job loss increases the burden of depressive symptoms among older Americans of limited means and that unemployment is one of the key mechanisms by which this occurs. The rationale for this project is that no one has yet analyzed data from the Health and Retirement Study (HRS) using a counterfactual framework or leveraging the full richness of the longitudinal data, and doing so will be essential for identifying mechanisms and thus interventions to alleviate depressive symptoms among older adults. The hypothesis will be tested by pursuing two specific aims: 1) Compare depressive symptoms burden in HRS under the observed employment histories to what would have happened if no one had ever suffered an involuntary job loss during follow-up. 2) Compare depressive symptoms burden in HRS under the observed employment histories to what would have happened if everyone who experienced a job loss during follow-up had soon been reemployed. For both aims, the parametric g-formula will be applied to estimate counterfactual outcomes under hypothetical interventions while controlling for time-varying confounding. The proposed research is innovative because, instead of comparing those who lost a job to those who did not, it frames the question in terms of hypothetical interventions on employment to estimate changes in the burden of depressive symptoms that would have been observed in the whole population under those interventions. The proposed research is significant because more than half of Americans in this age group will experience an involuntary job loss; the rigorous analysis proposed will provide estimates of both the corresponding burden of depressive symptoms and the extent to which these symptoms can be mitigated by reemployment, ultimately helping to set priorities for interventions.