The number of adults who lost coverage due to unemployment over those months is higher than have ever lost insurance in a single year, The New York Times reported.
The increase in uninsured laid-off workers during the study period was nearly 40% higher than the highest previous increase of 3.9 million, which occurred during the 2008-09 recession, according to the study from the nonpartisan consumer advocacy group Families U.S.A.
Nearly half (46%) were in five states: California, Texas, Florida, New York, and North Carolina, the Times reported.
In the 13 states that didn't expand Medicaid -- including Texas, Florida and North Carolina -- 43% of laid off workers became uninsured, nearly double the rate of 23% in states that did expand Medicaid.
"We knew these numbers would be big," Stan Dorn, one of the study authors and director of Families USA's National Center for Coverage Innovation, told the Times. "This is the worst economic downturn since World War II. It dwarfs the Great Recession. So, it's not surprising that we would also see the worst increase in the uninsured."