Time to stock up on those “Forever” stamps: The U.S. Postal Service is proposing a 3-cent increase in the cost of mailing a letter, effective in January.

That would bring the cost of first-class stamps to 49 cents. The Postal Service also proposed increases for letters that weigh more than one ounce, postcards and letters to international destinations.

The price increases are necessary because of the “precarious financial condition” of the Postal Service and the “uncertain path toward enactment of postal reform legislation” in Congress, said Mickey Barnett, chairman of the service’s board of governors.

“However, if these financial challenges were alleviated by the timely enactment of laws that close a $20 billion budget gap, the Postal Service would reconsider its pricing strategy,” Barnett said. “We are encouraged by the recent introduction of comprehensive postal reform legislation in Congress, and despite an uncertain legislative process, we are hopeful that legislation can be enacted this year.”

The Postal Service lost $15.9 billion last year and expects to lose $6 billion this year. Even after defaulting on its requirement to prefund retiree health benefits, the Postal Service “has an intolerably low level of available liquidity,” it stated.

The Postal Regulatory Commission must sign off on the Postal Service’s price increases before they go into effect.

The Greeting Card Association hopes the commission will reject the proposed price increases.

“Raising rates or cutting critical services will exacerbate the Postal Service’s current predicament by driving away much-need mail volume to other competitors,” said Rafe Morrissey, GCA’s vice president of postal affairs.

GCA has issued a report outlining ways the Postal Service can save money without raising rates or cutting services.