While lenders have been focusing on the Paycheck Protection Program for small businesses, the Federal Reserve Board has revamped another loan program intended to help businesses affected by the coronavirus pandemic.

The Federal Reserve said in a statement Thursday that it had expanded the scope and eligibility for the Main Street Lending Program. The program, which has not yet launched, was created “to help credit flow to small and medium-sized businesses that were in sound financial condition before the pandemic,” the Federal Reserve said in the statement.

The Main Street program will be administered by the Federal Reserve Bank of Boston.

The Federal Reserve said it decided to expand the loan options available to businesses and the maximum size of businesses eligible for the program after receiving more than 2,200 letters from individuals, businesses and nonprofits about the proposed program.

“With the changes, the program will now offer more options to a wider set of eligible small and medium-size businesses,” the Federal Reserve said.

The program was initially intended for companies with up to 10,000 employees and $2.5 billion in revenue. The new guidelines will open the program to businesses with up to 15,000 employees or up to $5 billion in annual revenue.

The program also now has three loan options – called new, priority, and expanded – instead of two.

The minimum loan size – originally set at $1 million – has been lowered to $500,000 for the new and priority loan options. The expanded loan option will have a $10 million loan minimum. All loans will have a four-year term and a rate of LIBOR plus 3 percent.

Unlike PPP loans, Main Street loans are not forgivable. Loan repayments can be deferred during the first year for all three loan options. Differences among the options include risk retention by the lender and repayment terms.

Borrower’s income in considered for all three loan options, and “lenders will be able to apply their industry-specific expertise and underwriting standards to best measure a borrower’s income,” the Federal Reserve said.

Businesses that are eligible for the Main Street program can still participate even if they received PPP loans.

The funds for the program were appropriated through the CARES Act. The Treasury Department will make a $75 billion equity investment in a Special Purpose Vehicle established by the Boston Fed for the Main Street Program. The program will continue until Sept. 30, unless it is extended, according to a set of frequently asked questions also released on Thursday.

The Boston Fed will maintain the SPV, which will purchase up to $600 billion of participations in eligible loans. The Federal Reserve and Treasury could adjust the program’s size in the future, according to the FAQ.

The Federal Reserve said a start date for the program would be announced soon. It also said that it would evaluate a separate approach to meet the needs of nonprofit organizations.