The price of a first-class postage stamp in the United States was last 37 cents on January 7, 2006. This price was first established on June 30, 2002.
On January 8, 2006, the price of a first class stamp increased to 39 cents. A year later, the postal service released the Forever Postage Stamp. While still costing 39 cents, the new stamp guaranteed not needing to buy additional postage to augment a stamp once the price increased. Instead of being marked with the current monetary value, the Forever Stamp was simply marked first class. While not increased on a predictable schedule, changes in postage prices are directly linked to the rate of inflation.