Even before the pandemic, more than 18 million Americans at high risk for COVID-19 complications lacked adequate health insurance, according to a study published today in the Journal of General Internal Medicine.Researchers at Harvard Medical School in Cambridge, Massachusetts, and City University of New York at Hunter College in New York City analyzed data from the 2018 Behavioral Risk Factor Surveillance System of the Centers for Disease Control and Prevention (CDC).They found that 18.2 million people with chronic obstructive pulmonary disease, asthma, heart or kidney disease, diabetes, or body mass index of 40 kg/m2 or higher and those 65 years and older were uninsured or underinsured.