Coins of the United States dollar

1. The mass and composition of the cent changed to the current copper-plated zinc core in 1982. Both types were minted in 1982 with no distinguishing mark. Cents minted in 1943 were struck on planchets punched from zinc-coated steel which left the resulting edges uncoated. This caused many of these coins to rust. These "steel pennies" are not likely to be found in circulation today, as they were later intentionally removed from circulation for recycling the metal and by collectors. However, cents minted from 1944 to 1946 were made from a special salvaged WWII brass composition to replace the steel cents, but still save material for the war effort, and are more common in circulation than their 1943 counterparts.
2. The wheat cent was mainstream and common during its time. Some dates are rare, but many can still be found in circulation. This is partially due to the fact that unlike the formerly silver denominations (dollar, half dollar, quarter, and dime), the composition of the pre-1982 cent, nearly pure copper, is not so much more valuable over face value for it to be hoarded to the extreme extent of the silver denominations.
3. Nickels produced from mid-1942 through 1945 were manufactured from 56% copper, 35% silver and 9% manganese. This allowed the saved nickel metal to be shifted to industrial production of military supplies during World War II. Few of these are still found in circulation.
4. Prior to 1965 and passage of the Coinage Act of 1965 the composition of the dime, quarter, half-dollar and dollar coins was 90% silver and 10% copper. The half-dollar continued to be minted in a 40% silver-clad composition between 1965 and 1970. Dimes and quarters from before 1965 and half-dollars from before 1971 are generally not in circulation due to being removed for their silver content.
5. In 1975 and 1976 bicentennial coinage was minted. Regardless of date of coining, each coin bears the dual date "1776-1976". The Quarter-Dollar, Half-Dollar and Dollar coins were issued in the copper 91.67% nickel 8.33% composition for general circulation and the Government issued six-coin Proof Set. A special three-coin set of 40% silver coins were also issued by the U.S. Mint in both Uncirculated and Proof.
6. Use of the half-dollar is not as widespread as that of other coins in general circulation; most Americans use dollar coins, quarters, dimes, nickels and cents only, as these are the only coins most often found in general circulation. When found, many 50¢ coins are quickly hoarded, spent, or brought to banks. As large numbers of half dollars are typically held by banks or available to order, they are often sought after by coin roll hunters for the purpose of searching for silver coins, proofs, and coins not intended for circulation.
7. The Presidential Dollar series features portraits of all deceased U.S. Presidents with four coin designs issued each year in the order of the president's inauguration date. These coins began circulating on February 15, 2007. Starting 2012, these coins have been minted only for collectible sets because of a large stockpile.
8. The Susan B. Anthony dollar coin was minted from 1979 to 1981 and 1999. The 1999 minting was in response to Treasury supplies of the dollar becoming depleted and the inability to accelerate the minting of the Sacagawea dollars by a year. 1981 Anthony dollars can sometimes be found in circulation from proof sets that were broken open, but these dollars were not minted with the intent that they circulate.
9. Although dollar coins have not been struck for circulation since 2011, the American Innovation dollar is considered a circulation coin by the US Mint.[8]

Non-circulating bullion coins have been produced each year since 1986. They can be found in gold, silver, platinum (since 1997), and palladium (since 2017). The face value of these coins is legal as tender, but does not actually reflect the value of the precious metal contained therein. On May 11, 2011, Utah became the first state to accept these coins as the value of the precious metal in common transactions. The Utah State Treasurer assigns a numerical precious metal value to these coins each week based on the spot metal prices. The bullion coin types include "S" (San Francisco, 1986-1992), "P" (Philadelphia, 1993 - 2000), and "W" (West Point, New York, 2001–present).[9]

Metal	Type	Face Value	Images		Specifications
			Obverse	Reverse	Diameter	Fineness	Content	Dates
Silver	America the Beautiful silver bullion coins	25¢		see article: America the Beautiful quarters	76.2 mm	999 fine	5.00 ozt (155.52 g)	2010 – 2021
	American Silver Eagle	$1			40.6 mm		1.00 ozt (31.10 g)	1986 – present
Gold	American Gold Eagle	$5			16.5 mm	916 fine (22 karat)	0.10 ozt (3.11 g)	1986 – present
		$10			22.0 mm		0.25 ozt (7.78 g)	1986 – present
		$25			27.0 mm		0.50 ozt (15.55 g)	1986 – present
		$50			32.7 mm		1.00 ozt (31.10 g)	1986 – present
	American Buffalo	$5			16.5 mm	999.9 fine (24 karat)	0.10 ozt (3.11 g)	2008
		$10			22.0 mm		0.25 ozt (7.78 g)	2008
		$25			27.0 mm		0.50 ozt (15.55 g)	2008
		$50			32.7 mm		1.00 ozt (31.10 g)	2006 – present
	American Liberty high relief gold coin	$100	see article: American Liberty high relief gold coin		30.61 mm		1.00 ozt (31.10 g)	2015 – present
Platinum	American Platinum Eagle	$10			16.5 mm	999.5 fine	0.10 ozt (3.11 g)	1997 – 2008
		$25			22.0 mm		0.25 ozt (7.78 g)	1997 – 2008
		$50			27.0 mm		0.50 ozt (15.55 g)	1997 – 2008
		$100			32.7 mm		1.00 ozt (31.10 g)	1997 – present
Palladium	American Palladium Eagle	$25			32.7 mm	999.5 fine	1.00 ozt (31.10 g)	2017 – present
These images are to scale at 2.5 pixels per millimetre. For table standards, see the coin specification table.

Modern commemoratives have been minted since 1982. A list is available here.