The U.S. Postal Service continues to hemorrhage money, with a loss of $2.2 billion in the most recent quarter, CNNMoney reported.

The national mail service said Tuesday that it expects to have a cash shortfall and reach its statutory borrowing limit by the time its fiscal year ends in September. That means the agency could be forced to default on some of its payments to the federal government.

Postmaster General Patrick Donahoe said the service is still seeking changes to federal

laws that would allow it to change its business model and potentially save enough money to avoid a default.

“The Postal Service may return to financial stability only through significant changes to the laws that limit flexibility and impose undue financial burdens,” Donahoe said in a statement.

At issue is a 2006 law requiring the service to pay between $5.4 and $5.8 billion into its prepaid retiree health benefits each year. In addition, the agency is seeking Congressional approval to eliminate Saturday mail service.

The postal service has estimated that moving to five-day service could save $3.1 billion. But the Postal Regulatory Commission, which oversees the agency, issued an advisory in March that put the savings at a much more modest $1.7 billion.