Washington – In an effort to make it more difficult to counterfeit money, the US government has redesigned the $100 bill, adding new security features.

The blue 3-D Security Ribbon on the front of the new $100 note contains images of bells and 100s that move and change from one to the other as you tilt the note. The Bell in the Inkwell on the front of the note is another new security feature. The bell changes color from copper to green when the note is tilted, an effect that makes it seem to appear and disappear within the copper inkwell.

The redesigned $100 bill was unveiled at a ceremony in Washington by Treasury Secretary Tim Geithner and Federal Reserve Chairman Ben Bernanke. The redesigned $100 bill is to be released on February 10, 2010, in order to give the government time to educate the public.

Bernanke noted that as much as two-thirds of U.S. currency circulates outside of the Country, while saying the 6.5 billion $100 bills currently in circulation will remain legal tender.

“U.S. currency users should know they will not have to trade in their older design $100 notes when the new ones begin circulating,” said Bernanke.

The $100 bill is the last U.S. currency to undergo redesign. The redesign of U.S. currency began in 2003 with the $20 bill, which was soon followed by the $50, $10 and $5. Only the $1 dollar bill has been left out of the program.

$100 bills are the most counterfeited U.S. currency outside the United States, $20 bills remain the highest within the U.S.