Small Sized Currency was issued between 1928 and the present (and is still being issued today). It is called "Small Sized Currency" because issues of Series 1928 and later of U.S. currency were about 25% smaller than the currency issued earlier. (Go to Large Sized Currency for more information on pre-1928 U.S. currency.) Because this is the only size of U.S. currency that most people remember, it is also called "Modern Currency".

It is catagorized into 6 different classes as visually displayed below.