What Is a Mint Mark on a Coin and What Does It Mean?
Understand coin mint marks: what they are, where to find them, and how they reveal a coin's unique origin and history.
A mint mark on a coin is a small letter or symbol indicating its production facility. These identifiers help categorize coins by their place of creation and offer insight into their production history.
What is a Mint Mark?
The primary purpose of mint marks historically involved accountability and quality control. If issues arose with a coin’s metallic composition or weight, the mark allowed authorities to trace it back to the originating facility and address discrepancies. This system ensured each mint branch adhered to established production standards.
The practice of using mint marks in the United States began in 1838, following the Coinage Act of 1835, which authorized the establishment of branch mints. Before this, the Philadelphia Mint, as the sole operating facility, did not require a distinguishing mark. With the opening of new mints, such as those in Charlotte, Dahlonega, and New Orleans, unique letters were introduced to identify their respective outputs. This development highlights the role of mint marks in maintaining oversight across a growing national coinage system.
Locating Mint Marks on Coins
The placement of mint marks on U.S. coins varies by denomination and year. Before 1968, marks were commonly on the reverse (tails) side. In 1968, the U.S. Mint began placing them on the obverse (heads) side for most circulating coins.
On Lincoln cents, the mint mark is below the date on the obverse. For Jefferson nickels, the mark is near the date on the obverse since 1968; earlier issues (1938-1964) had it on the reverse to the right of Monticello. Wartime silver nickels (1942-1945) feature a prominent mint mark on the reverse, above the Monticello dome.
Roosevelt dimes produced since 1968 display their mint mark above the date on the obverse. Washington quarters minted from 1968 onward have the mark on the obverse, either behind Washington’s hair or below “IN GOD WE TRUST” for state quarters. Kennedy half dollars from 1968 to the present also feature their mint mark on the obverse, below President Kennedy’s bust.
Common U.S. Mint Marks and Their Meanings
Several letters appear as mint marks on U.S. coins, each representing a specific mint facility.
The “P” mint mark signifies coins produced at the Philadelphia Mint. Historically, coins from Philadelphia often did not bear a mint mark, particularly before 1979, with exceptions like wartime silver nickels (1942-1945) and Susan B. Anthony dollars starting in 1979. The “P” mark began appearing on all Philadelphia-produced coins, except cents, from 1980 onward.
The “D” mint mark denotes coins struck at the Denver Mint, in operation since 1906, which produces a large volume of circulating coinage.
The “S” mint mark identifies coins from the San Francisco Mint, known for its production of proof coins and, historically, circulating coinage until 1955 and again from 1968.
The “W” mint mark indicates coins from the West Point Mint, which primarily specializes in bullion and commemorative coins. The “W” mark first appeared on a circulating coin in 2019.
The Role of Mint Marks in Coin Identification
Mint marks are important for identifying U.S. coins. These small letters allow collectors to distinguish between coins that appear identical in date and design but were produced at different facilities.
This distinction is important because production quantities vary greatly among mints for a given year and coin type. For instance, one mint might produce millions of a coin, while another issues only a few hundred thousand of the same coin in the same year. This difference in mintage figures directly impacts a coin’s scarcity.
A mint mark provides context regarding a coin’s production history and its place within U.S. coinage.