The ominous red spots are expanding across the nation in a newly updated map showing projections for how many counties could be without insurers selling Obamacare health plans in 2018.

The map was released Tuesday by the Centers for Medicare & Medicaid Services, the federal agency responsible for overseeing Obamacare.

In the last two weeks, four additional counties were added to the map, CMS said. The government agency predicts that 49 counties will be "red counties," which means Americans living there wouldn't have any options to choose from when they try to enroll in a health plan next year on a health exchange.

It is also projected that as many as 1,300 counties — over 40 percent of counties nationwide, representing 2.4 million exchange participants — could be "yellow counties" with only one issuer available for 2018.

"We continue to see a decline in issuer participation in the Health Insurance Exchanges leaving consumers with fewer and fewer insurance options," said CMS Administrator Seema Verma in the report. "I am deeply concerned about the crisis situation facing the individual market in many states across the nation."

It is largely the Midwest and Southern states being hit by insurance carriers pulling out, as well as Alaska. Most Northern and Western states are composed of "green counties," which have two or more carrier options for its residents to choose from.