Congress has extended the generous Cobra subsidies for the uninsured four times since they were implemented in February 2009, but Congress failed to pass a fifth extension before the last extension ran out on June 1, according to a report by National Public Radio.
With lawmakers increasingly worried about passing big spending measures before the November election, it's unclear whether Congress will pass the Cobra extension when it returns from recess next week.
About 500,000 workers who lost their jobs each month were eligible for the Cobra subsidy and up to one-third took advantage of it, according to the Obama administration.
Without the subsidy, which pays up to 65 percent of the insurance premium, a laid-off worker would have to pay more than $13,000 a year for family insurance.
Read NPR's report on Cobra insurance subsidies.