<p>Although the COVID-19 pandemic has affected everyone’s life in the United States, the experience of the pandemic differed considerably by age: the risk of hospitalization and death from COVID-19 increases exponentially with age. Using data from the 2013 and 2021 American Time Use Survey Well-Being Modules, this paper examines how various measures of subjective well-being have changed during the COVID-19 pandemic among two age groups in the United States: individuals aged 15–44 and those aged 45–85. The measures of subjective well-being analyzed include activity-level subjective well-being measures, such as happiness, pain, sadness, stress, tiredness, and meaningfulness, as well as overall life evaluation based on the Cantril ladder. The regression results indicate that younger people felt less happy, more stressed, and less tired during the COVID-19 pandemic because their time use patterns, such as activity types, timing, and with whom, changed. However, there was no change in the life evaluation of the younger group due to the pandemic. The older group, in contrast, felt more pain, sadder, and less meaningful during the COVID-19 pandemic, even after controlling for their health status and time use patterns, perhaps because they had lost many family members and friends to COVID-19. Their life evaluation increased during the COVID-19 pandemic, maybe because they began to better appreciate their life after the deaths of many people around them.</p>