Postal regulators on Tuesday approved a price hike of 3 cents for a first-class stamp, bringing the charge to 49 cents a letter.
The independent Postal Regulatory Commission said the change was justified by severe mail volume decreases since 2008.
The new price is effective Jan. 26 and will last no more than two years, allowing the Postal Service to recoup $2.8 billion in losses.
Regulators rejected a request to make the price hike permanent.
Bulk mail, periodicals and package service rates rise 6 percent.
The mail industry opposes the price increases. It says charities using mass mailings and bookstores competing with Amazon will suffer.
The Postal Service says it lost $5 billion in the last fiscal year.