As small and midsize law firms rush to claim a share of $350 billion in government-backed loans to keep their payrolls afloat, some are finding that their business models pose a special obstacle.

Starting April 3, small U.S. businesses have been able to start applying for the Paycheck Protection Program, a key part of the $2 trillion COVID-19 pandemic relief bill. Under the program, banks will loan up to $10 million to businesses with less than 500 employees on very favorable terms—two-year maturity and 1% interest rate.