Postage rate reductions include: First-class stamps — 47 cents (old rate, 49 cents) Each additional ounce for letters — 21 cents (old rate, 22 cents) First-class metered mail (first ounce) — 46.5 cents (old rate, 48.5 cents) Postcards – 34 cents (old rate, 35 cents) Certified mail — $3.30 (old rate, $3.45)