WASHINGTON (AP) -- The U.S. discriminates against blind people by printing paper money that makes it impossible for them to distinguish the bills' value, a federal appeals court ruled Tuesday.

The ruling upholds a decision by a lower court in 2006. It could force the Treasury Department to redesign its money. Suggested changes have ranged from making bills different sizes to printing them with raised markings.

The U.S. acknowledges that the design hinders blind people but it argued they had adapted; some relied on store clerks for help, some used credit cards and others folded certain corners to help distinguish the bills.

But the U.S. Court of Appeals for the District of Columbia Circuit ruled 2-1 that such adaptations were insufficient. The government might as well argue that, since handicapped people can crawl on all fours or ask for help from strangers, there's no need to make buildings wheelchair accessible, the court said.

The court also ruled that the U.S. failed to explain why changing the money would be an undue burden. The Treasury Department has redesigned its currency several times in recent years and adding features to aid the blind would come at a relatively small cost, the court said.

Other countries have added such features, the court said, and the U.S. never explained what made its situation so unique.