The 2021 (S) Silver Eagle is an Emergency Production Issue coin produced by the San Francisco Mint to help meet demand for the Silver Eagles during the COVID-19 pandemic. A total of 1000000 Silver Eagle bullion coins were produced at the San Francisco Mint in 2021. The San Francisco coins are identified by the serial numbers on 500-coin monster boxes. Because there are no "S" mint marks on these coins and they are nearly indistinguishable from West Point silver eagles - these serial numbers are the best way to identify these coins.