The present study investigated whether higher subjective executive functioning and learning new skills related to better mental health across adulthood during the COVID-19 pandemic. Participants (n = 133) were recruited from Southern California, USA across two different timepoints. A subset of participants over the age of 58 years old, who previously participated in a skill learning intervention (n = 52) that increased objective executive functioning, also were included in the present study. Worse subjective executive functioning (EF) during the COVID-19 pandemic predicted worse mental health across adulthood. In addition, learning new skills may have helped adults adapt better to changes during the pandemic to increase mental health. These findings highlight the importance of cognitive abilities and learning new skills on mental health.  Our findings provide a more nuanced view of the benefits and costs of adaptation via skill learning on adult mental health during the COVID-19 pandemic. Learning new skills could be associated with better mental health outcomes and we see this during the second timepoint of the COVID-19 pandemic. In addition, worse subjective cognitive abilities could lead to worse mental health outcomes. Our results suggest that better cognitive abilities and learning new skills are important for mental health.