The 1916-D Mercury dime is one of the rarest 20th-century regular-issue business-strike coins. With a mintage of only 264,000 pieces, the 1916-D dime had a lower mintage than any of the regular-issue Lincoln cents (including the 1909-S VDB) and many of the important Morgan dollar issues, including the rare 1889-CC.
There were 22,180,080 Mercury dimes minted in Philadelphia and 10,450,000 struck in San Francisco, so why is the 1916-D so rare? Reportedly, United States Mint officials were focused on stepping up mintage of the 1916-D Barber quarter, which was in its last year of production. And, in the scope of the Mercury dime series, which replaced the Barber dime in 1916 and ran until 1945, the tiny Denver Mint output of 1916 proved to be an anomaly for the series.
Mercury dimes across the board are largely common, except for the 1921 and 1921-D business strikes and the 1942/1 and 1942/1-D overdates. Therefore, assembling a series collection isn't necessarily difficult for the most part, but the handful of semi keys and varieties, plus the 1916-D key date, provide this series a monumental complexity that has challenged collectors for generations now.
Professional Coin Grading Service (PCGS) CoinFacts reports there are only 10,000 or so 1916-D Mercury dimes estimated to survive across all grades -- far scarcer than the coin's mintage of 264,000 pieces may suggest. Prices begin at around $900 to $1,000 for examples even in Good-4 and climb steadily from there. Uncirculated examples are five-figure coins, with a typical MS-63 commanding $13,500 to $15,000. Sharply struck Full Bands specimens are most desired by Mercury dime enthusiasts and serve as the impetus for many record prices in the series, including a six-figure hammer price for the 1916-D; early in 2020, a 1916-D MS-67 Full Bands specimen with a Certified Acceptance Corporation sticker fetched $204,000 at auction!