The U.S. Postal Service has launched a pilot program to offer some banking services in four cities. Customers in Washington, D.C.; Falls Church, Virginia; Baltimore, Maryland; and the Bronx in New York City can now cash paychecks and other types of checks up to $500 for a fee that’s much lower than private cashing companies. The service, if expanded, could provide a government-run, more accessible option to the 14 million U.S. residents who are underbanked or unbanked.