What is the flat rate for medium box priority mail

The flat rate for a Medium Box Priority Mail in the United States is $14.35 as of 2023. This rate applies to boxes that weigh up to 20 pounds and measure up to 13 inches long, 11 inches wide, and 5.5 inches high.

Here are the current flat rates for Priority Mail Medium Boxes:

Please note that these rates are subject to change, so it's always a good idea to check the official USPS website or consult with a postal representative for the most up-to-date information.