The US Federal Reserve on Friday opened its “Main Street” loan program to nonprofits, allowing education, health, social service and other groups with as few as 10 employees to tap central bank funding. The announcement extends the Fed’s pandemic safety net to a new sector of the economy, one that may face unique financial struggles given the likely dip in charitable donations during the health crisis, and the possible blow to things like school enrollment and participation in youth sports leagues. The Fed estimated that the thousands of non-profits eligible for loans, from hospitals and colleges to small community groups, account for about 10% of US jobs, or roughly 13 million people.