Although the COVID-19 pandemic has affected everyone’s life, 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 pandemic among two age groups in the United States: individuals aged 15 to 44 and those aged 45 to 85. The measures of subjective well-being include life evaluation and activity-level subjective well-being measures: happiness, pain, sadness, stress, tiredness, and meaningfulness. The results indicate younger people felt less happy, more stressed, and less tired during the 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. The older group felt more pain, sadder, and less meaningful during the 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 pandemic, maybe because they began to better appreciate their life after the deaths of many people around them.