The PPP liquidity facility created by the Fed was initially set to expire on March 31.
The central bank has been offering low-interest loans through the facility, which has already been extended twice since the crisis began last year.
Federal Reserve Chairman Jerome Powell stated on Thursday that the United States likely won't reach maximum employment this year.
The issue will depend on how "strongly" the economy recovers and activity picks up after the coronavirus pandemic has been put under control, the official noted.
"There's a lot of ground to cover to get back to maximum employment," Powell said, asserting that increasing vaccinations against Covid-19 and providing more financial support could stimulate faster job creation.