Objectives: This study extends the field of retirement and health by examining the impacts of daily stressors on morning cortisol levels in 253 retirees between 55 and 75 years of age (M = 66.80, SD = 4.96) and the moderating roles of age and gender. Method: Participants derived from the second wave of the Daily Diary Study portion of the National Survey of Midlife Development in the United States (MIDUS-II). Across eight consecutive evenings, participants completed telephone interviews about their daily experiences and provided saliva samples across 4 days. Results: Findings from the multilevel models showed that in the context of navigating the day-to-day responsibilities, older retirees were at a greater risk for subsequent hypothalamic pituitary adrenal (HPA) dysregulation than younger retirees. Discussion: Together, better identification of the associations between daily stressors and physiological functioning will help contribute to the knowledge on ways to promote greater quality of life in retirement.