The coronavirus outbreak has forced millions out of work and the federal-state health program for low-income people could face unprecedented strains as many states don’t necessarily have the resources or systems in place to meet the demand.

As the coronavirus roils the economy and throws millions of Americans out of work, Medicaid is emerging as a default insurance plan for many of the newly unemployed. That could produce unprecedented strains on the vital health insurance program, according to state officials and policy researchers.

Americans are being urged to stay home and practice “social distancing” to prevent the spread of the virus, causing businesses to shutter their doors and lay off workers. The Labor Department reported Thursday that more than 6.6 million people signed up for unemployment insurance during the week that ended March 28. This number shattered the record set the previous week, with 3.3 million sign-ups. Many of these newly unemployed people may turn to Medicaid for their families.

Policymakers have often used Medicaid to help people gain health coverage and health care in response to disasters such as Hurricane Katrina, the water crisis in Flint, Michigan, and the 9/11 terrorist attacks. But never has it faced a public health crisis and economic emergency in which people nationwide need its help all in virtually the same month.

“Medicaid is absolutely going to be in the eye of the storm here,” said Joan Alker, executive director of the Georgetown University Center for Children and Families. “It is the backbone of our public health system, our public coverage system, and will see increased enrollment due to the economic conditions.”