The price to send a first-class letter will increase to 41 cents today.
David Partenheimer, a spokesman with the U.S. Postal Service, said postage increases help adjust for inflation and typically cover the postal service's operating expenses, like costs associated with fuel and employee benefits.
Partenheimer said the USPS introduced the Forever stamp last month. The stamp can be purchased for 41 cents, and it retains its first-class value regardless of future postage rate increases, he said.
The price of stamps last increased in January 2006, from 37 cents to 39 cents.