The 1991 United States Coin Set (Birthday Set) is a collectible 5 coin set featuring denominations of 50 cents, 25 cents, 10 cents, 5 cents, and 1 cent. Made of clad composition, these coins were minted in Denver and Philadelphia in 1991 as part of the U.S. Mint certification program. Each coin is in business strike type and of ungraded grade. This set is a valuable addition to any collection of US coins, especially for those with a birthday in 1991.