About 75 percent of First-Class Mail will keep its current service standards, according to USPS, and 14 percent will see an improvement in delivery times. Some individuals could experience slower times; however, USPS has stated that delivery times won't exceed the current five-day service standard for First-Class Mail.

The formal changes follow the resignation of Postmaster General Louis DeJoy and a series of difficult months for the USPS with a flurry of other course corrections being implement

USPS changes are aimed to cut costs. Will it take longer for your mail, packages to be delivered? What we know about new delivery standards.