The number of Americans struggling to pay their mortgages has skyrocketed as the economy reels from the coronavirus pandemic, with nearly 3 million Americans behind by at least one month on their mortgage payments in the week ending April 12, according to the Mortgage Bankers Association.

Nearly 6% of all mortgages were in forbearance, the industry term for being behind on payments. The week before, 3.7% of home loans were past due by at least a month. The first week of March, just 0.25% of such loans were past due by a month.

This high a figure on a nationwide level is unprecedented, said Mike Fratantoni, MBA's chief economist.

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"You might have seen this high of a share in Houston after Hurricane Harvey, but it was always a local phenomenon," he said. "What's different this time is it's national. To have 6% of mortgage loans in forbeareance, that's about 3 million homeowners saying they can't make their mortgage payments due to COVID-19."

Fratantoni expects that number to keep rising, citing an additional 1.8% of homeowners who called banks to request forbearance last week.

"As we get to the time when May payments are due, I expect to see those numbers going up again," he said. "We are hopeful that, now that some of the stimulus payents are arriving and unemployment benefits are expanded, that can provide some cushion to keep these numbers from going higher too fast."

More than 22 million Americans have filed for jobless benefits in the past month, and homeowners are taking advantage of a provision in the CARES Act that bars eviction of homeowners whose mortgages are backed by Fannie Mae or Freddie Mac. The law also lets homeowners ask for their payments to be reduced or deferred for 12 months with no penalties.

More than 8.2% of mortgages backed by Ginnie Mae were in forbearance, according to the MBA survey, compared with 4.64% of mortgages backed by Fannie Mae and Freddie Mac.

The CARES Act does not protect mortgages that are not backed by the government, which make up about half of all mortgages nationwide.

— CBS News' Khristopher Brooks contributed reporting.