Senator McCaskill billed taxpayers for an airplane flight that took her to the 2007 Democratic Party political meeting, but has paid for it since.
A spokeswoman for McCaskill says the Senator is embarrassed about the mistake.
Billing taxpayers for political travel is a violation of congressional ethics rules.
McCaskill had submitted a bill for one thousand, 220 dollars for a flight from St. Louis to Hannibal along with about 89 thousand dollars in travel expenses submitted to the U.S. Treasury.