This study examines population-weighted, sex-and age-disaggregated official COVID-19 mortality data (as of July 25, 2020) from the United States to understand gender gaps (men-women) across age. The analysis yields three key findings: (1) all age groups report about 8 percentage points more deaths among men than women; (2) non-elderly adults (< 65 years) have a larger gender gap in reported mortality than elderly (≥ 65 years) adults; and (3) the gender gap in reported mortality varies across states, with thirteen states reporting more deaths among women than men. Women's lack of access to healthcare and a state's healthcare capacity have a significant correlation with the gender gap in reported mortality for both non-elderly and elderly adults. The findings underscore the possible presence of an underreporting bias against women in the officially reported COVID-19 death tolls in the US. KEYWORDS Healthcare, pandemic, SARS-CoV-2, gender gap in mortality, poverty and inequality JEL CODES: I10, J31, I3 HIGHLIGHTS • The COVID-19 gender mortality gap in the US is similar to that of other developed nations. • While men are more likely than women to die from COVID-19 infections, the reverse is true in thirteen states. • The gap is high in states with low hospital capacity and women's low healthcare access. • COVID-19 fatalities among women are more likely to be underreported than those among men.