Proof Error Coins Elude the US Mint

In 2005 a leading variety expert announced the discovery of proof 1998 and 1999 cents that had been struck with business strike reverse dies. These pieces can be distinguished by extremely close spacing between the letters "AM" in "AMERICA." This announcement resulted in many collectors and experts searching through their coins to find this elusive new variety.

In 1994 the mint modified the reverse design for all proof Lincoln Cents. Until that year, all proof cents should have the same reverse design of 1994. The reverse for all proof cents should bear the letters "AM" in America spaced apart from each other. On business strikes the "AM" should be nearly touching.

U.S. proof coins are typically produced with great care. They are handled and inspected by numerous skilled mint employees to assure the highest standards of production quality and errors of this type are normally quite rare. A prior incident occurred back in 1972 on the Eisenhower dollar when a proof reverse die was also used to strike business strike coins. Once this error was publicized, the "Type 2" design became highly sought after by collectors and ultimately the key to the series.

Recently a 1998-S "Close AM" cent was sent in to PCGS for authentication. After thorough research and information from some of the top known experts, the example was believed to be one of fewer than ten known. The actual number produced is, of course, unknown.

The 1998-S proof cent has a mintage of just under 3 million pieces, and so far it is difficult to believe there have been fewer than 10 reported. While the 1999-S "Close AM" variety tends to be more available than its 1998 counterpart, it remains very tough to locate. With over 3 million proof cents having been produced in 1999, there might still be more out there waiting to be found.

Current values for the 1999-S "Close AM" variety range anywhere from $250 to $3,500, depending on condition. The 1998-S is extremely rare today. With fewer than 10 known, prices can range anywhere from $1,500 up to $5,000. The average condition for both these dates tends to be high and most examples grade PR 67 or higher.