WASHINGTON — The U.S. Postal Service reported a $2.5 billion net loss for the fiscal third quarter, nearly $600 million less of a loss than the same quarter last year, and urged a series of actions from Congress to address its mounting financial crisis.

U.S. Postmaster General David Steiner said legislation passed by a Senate committee to add dozens of new ZIP codes could cost the cash-strapped postal service $800 million and said the agency is seeking approval for a new stamp price hike in January rather than waiting until July 2027.

Steiner said without action from Congress this year, “our plans would certainly have to entail changes that will impact service like taking a look at our service levels and closing thousands of unprofitable post offices, as well as raising prices.”

In June he warned: “The bottom line is that we are out of cash. We are borrowing from our employees’ retirement funds to continue operations,” Steiner said, urging Congress to compensate it for money-losing operations and make other reforms.

In March, USPS hired restructuring advisers to help address its ​financial troubles.

One key question is whether USPS should continue to deliver to 170 million addresses six days a week, which costs $3.4 billion annually — and 70% of those routes lose money, Steiner said. About 58% of its 18,000 post offices also lose money.

The Postal Service has reported net losses of more than $120 billion since 2007, as first-class mail, its most profitable product, has fallen sharply with the shift to digital communication even as the ​agency must maintain costly ​nationwide delivery operations.

USPS ⁠said in May it was suspending nonessential spending on travel, office supplies and consultants.

In May, the ⁠Postal Service said it would temporarily suspend employer payments for a federal pension program and raised the price of first-class mail stamps to 82 cents from 78 cents, effective July ⁠12.

Suspending ​employer pension contributions will conserve $2.5 billion through Sept. 30 ​and potentially $15 billion through 2030.