Currency notes of denominations above $100 are not available from the Department of the Treasury, the Federal Reserve System, or the Bureau of Engraving and Printing. On July 14, 1969, the Department of the Treasury and the Federal Reserve System announced that currency notes in denominations of $500, $1,000, $5,000, and $10,000 would be discontinued immediately due to lack of use. Although they were issued until 1969, they were last printed in 1945.
And they're still legal tender! I didn't know we had bills over $100 in the US.