Despite a Warning From Its Regulator, USPS Will Slow Down Some Package Delivery Starting in May "Currently, USPS aims to deliver all First-Class packages in two or three days. Beginning May 1, that will shift to just 68%, with 17% taking four days and 15% taking five days. The change is part of Postmaster General Louis DeJoy’s 10-year strategy to steady postal finances and follows USPS slowing down its delivery standards for about 40% of First-Class mail last year."