On January 22, 2017 the price of a stamp increased 2 cents from 47 cents to 49 cents. Retail Prices effective January, 22 2017. Letters that meet one or more of the nonmachinable characteristics in DMM 101.1.2 are subject to the $0.21 nonmachinable surcharge. Large envelope-sized pieces that are rigid, nonrectangular, or not uniformly thick pay parcel prices. For weights over 3.5 ounces, see Large Envelopes prices.