The agency said it would likely lose $18 billion in the next three years if steps were not taken to address the financial hemorrhaging, CNNMoney reported.
In its most recent financial plan submitted to Congress, besides adding a nickel to the cost of a stamp, the Postal Service recycled some familiar ideas, including closing thousands of facilities, shaving home delivery from six to five days a week and adding a day to its delivery schedule.
The plan also calls for cutting 155,000 jobs, mostly through attrition.
"The plan we have developed requires a combination of aggressive cost reduction, rethinking the way we manage our healthcare costs, and comprehensive legislation to reform the business model of the Postal Service," said Postmaster General Patrick Donahoe.
But the National Association of Letter Carriers said $3.1 billion of the $3.3 billion in losses in the final quarter of 2011 came from a law that requires the service to pre-fund health benefits for future retirees.
In addition, "charging more for reduced service is not a rational plan for any business, including the U.S. Postal Service," said Fredric Rolando, president of the National Association of Letter Carriers.