The proposal, which must be approved by the Postal Regulatory Commission, would raise mailing services product prices by 7.8%.

USPS in November reported a $6.5 billion net loss for the 12 months ending Sept. 30 as first-class mail fell to the lowest volume since 1968. Stamp prices are up 36% over the last four years since early 2019 when they were 50 cents.

USPS has been aggressively hiking stamp prices and is in the middle of a 10-year restructuring plan announced in 2021 that aims to eliminate $160 billion in predicted losses over the next decade and had previously forecast 2023 as a breakeven year.

USPS has been raising stamp prices twice yearly and has said it expects its "new pricing policy to generate $44 billion in additional revenue" by 2031.

A number of lawmakers have raised concerns about USPS planned changes to its processing and delivery network that could impact timely deliveries.

First-class mail volume fell 6.1% in the 12 months ending Sept. 30, 2023 to 46 billion pieces and is down 53% since 2006 -- to the lowest volume since 1968 -- but revenue increased by $515 million because of higher stamp prices.

First-class mail, used by most people to send letters and pay bills, is the highest revenue-generating mail class, accounting for $24.5 billion, or 31% of USPS 2023 revenue.

In April 2022, U.S. President Joe Biden signed legislation providing USPS with about $50 billion in financial relief over a decade. Postal unions are pressing the White House to accurately value USPS pension assets and liabilities.

In February, the White House nominated former Labor Secretary Marty Walsh to serve on the U.S. Postal Board of Governors after more than 80 Democrats in the U.S. House of Representatives had written Biden urging him to nominate candidates to open seats, complaining about slow deliveries and increased costs.