Though all countries struggled to respond to COVID-19, the United States' poor performance during the pandemic was unexpected. Despite having more pandemic preparedness capacities than other countries, the United States experienced more than one million COVID-19 deaths, which has contributed to historic declines in national life expectancy. Though some have raised questions as to whether preparedness capacities matter, data that appropriately address cross-country differences in age structure and surveillance approaches show that higher levels of national preparedness was associated with reduced mortality during the pandemic. The United States, however, stands out as a clear outlier in COVID-19 mortality comparisons with other highly prepared countries. We subsequently discuss and summarize the specific gaps in US pandemic preparedness that may have hampered COVID-19 responses in the country. Additional data and research are urgently needed to more accurately understand why the US did not make better use of its prepandemic advantages.