In a hearing before a House Committee, the non-partisan, investigative arm of Congress will try to convince the U.S. why coins make more sense.
The GAO says a one dollar coin typically costs about 30 cents for the U.S. Mint to produce, but the government can sell them to Americans for a dollar each.
In contrast, producing a dollar bill is much cheaper; it only costs about 5 cents apiece. However, they wear out far more quickly than coins, and typical last less than five years.
This won't be the first time the GAO makes its case; it's been recommending the change for 22 years.
But it's a hard sell.
Most Americans, the vending machine industry and even the Federal Reserve are staunchly opposed to the switch.