But while Panama uses US coins, there are also Panamanian versions of the coins as well, and the peso (50-cent piece) is actually used with some frequency. All the coins have the same composition as their US counterparts. I have not been able to figure out yet where their coins are minted however. And they do not seem to mint every year. I have found quarters, dimes, nickels, and pennies from 1996 (when the shields got smaller and other design changes were made) and 2001 for example, but nothing in between and only quarters since, with 2003, 2005, and 2008 versions, each with a different design. As they are the same size and have the same value as their US versions, you'd have no trouble spending Panamanian coins in the United States.
In recent years, the US Mint has begun a program of changing the obverse or reverse of US coins, making your pocket change much more interesting to look at and much more popular with coin collectors, who now try to hoard a copy of each style. Panama has been making small changes for years. Here are some of the versions I've collected in our time here.
Similar to in the states, one cent is called un centavo. But not a "penny".
The five cent piece in Panama is an integral part of the monetary system. Instead of a "nickel", it is called un real. And many items are commonly priced in reales. For instance, if you buy a soda for 20 cents, the shopkeeper will likely say, "cuatro reales", or "four nickels". This is true at least up to items that cost a dollar. So something that costs 75 cents would be "quince reales" or "fifteen nickels", not "setenta-cinco centavos".
(These five cent pieces sometimes have the shield, sometimes the face of Sara Sotillo, a Panamanian educator born around 1900 and instrumental in the development of teachers rights and responsibilities.)
You'll have to refer to the picture above of all the coins to judge the size, but Panamanian ten cent pieces (un decimo de balboa) are the same smallness as US dimes and are probably the most boring of Panamanian coins.
(Panamanian ten cent pieces don't have their own name, like "dime". These two reverses show two shield designs, the newer slightly smaller.)
To me, the 25-cent piece is the most dynamic. Here is the obverse (the Balboa profile) and five of the six reverse designs I have seen (I was missing the Childrens' Hospital, the newest design, that day).
(Panamanian Quarters, with from top left, the original shield design (at least 1966 to 1993), the smaller shield design without bottom fronds (1996 and 2001), the Panama Vieja tower (2003), the Puente del Rey (2005), and the Protégete Mujer (2008) with a Protect Women ribbon.)