WASHINGTON — Some first-time home buyers will get a break on their down payments through programs announced Monday by mortgage giants Fannie Mae and Freddie Mac as the firms try to jump-start the housing market by making it easier for more borrowers to qualify for a mortgage.

Fannie and Freddie will soon allow for mortgages with a down payment as low as 3 percent of the purchase price – instead of the 5 percent currently required – as long as one of the borrowers on the mortgage has not owned a primary residence within the past three years. The changes take effect Dec. 13 at Fannie and March 23 at Freddie.

In a call with reporters Monday, Fannie and Freddie officials said it’s too early to tell how many borrowers will take advantage of the programs. But they also said they expect many lenders to offer them. The Federal Housing Finance Agency, which oversees both companies, said these low-down-payment loans will probably be a small share of both firms’ businesses.

Fannie and Freddie do not make loans. They buy them from lenders, package them into securities and sell them to investors. For a fee, they guarantee the mortgages and pay investors if the loans default.

The down-payment changes mark the latest effort by government regulators to help first-time buyers who have been shut out of the housing market in recent years. Since the market unraveled, lenders have been turning away potential buyers by demanding unusually high credit scores and imposing tough standards on government-backed loans, including those of Fannie and Freddie.

The industry, which was forced by regulators to buy back billions of dollars in loans after the housing bust, has said that it’s trying to insulate itself from more financial penalties and lawsuits. It repeatedly has ignored pleas from the White House and government regulators to ease lending criteria.

Fannie, Freddie and their regulator responded by taking a number of steps to address lender concerns, and agreed to clarify the circumstances under which lenders are required to buy back loans. Some lenders (most notably Bank of America) have said in the past that these changes are not likely to encourage them to offer low-down-payment loans. On Monday, Bank of America said that it is re-evaluating now that program details have been released.

Fannie and Freddie say the feedback they’re receiving suggests that many lenders they work with will embrace the new 3 percent down options, and industry experts agree.

“I’m confident that the majority of the lending community is going to take part in these programs,” said David Stevens, chief executive of the Mortgage Bankers Association. “They’re more confident about the risks they face in extending these loans.”

Some Republican lawmakers, including Rep. Jeb Hensarling of Texas, have said the Fannie and Freddie low-down-payment programs are a return to the lax lending standards that contributed to the foreclosure crisis. But Fannie and Freddie officials insist they are not.

On Monday, company officials emphasized that they will only buy plain-vanilla, fixed-rate mortgages belonging to borrowers who can document their ability to repay a mortgage.

“These underwriting guidelines provide a responsible approach to improving access to credit while ensuring safe and sound lending practices,” Mel Watt, director of the Federal Housing Finance Agency, said in a written statement.

Both Fannie and Freddie had previously accepted 3 percent down-payment mortgages. But Fannie stopped purchasing them in late 2013 unless the loans were made through state and local housing finance agencies. Timothy Mayopoulos, Fannie’s chief executive, has said his company’s long experience with these loans shows that they perform well.

Under the new plan, Fannie also will allow borrowers with up to 97 percent equity in their homes to refinance. Previously, it only allowed refinances for people with 95 percent equity. It is also allowing limited cash-out refinances so that borrowers can pull enough cash out to help pay for the closing costs. The amount of cash would be limited to 2 percent of the loan amount or $2,000, whichever is less.

Freddie, Fannie’s smaller rival, said that it has not purchased 3 percent down-payment loans in years, which is why it will take longer to get its program up and running. To qualify, Freddie is requiring that home buyers participate in a borrower education program first.

Fannie and Freddie only buy loans with less than 20 percent down if they carry private mortgage insurance, so even if some of the 3 percent down loans were to default, taxpayers are not in line to take the first hit – the mortgage insurance companies are.