A short-term, fixed-income security issued by the U.S. Treasury to cover cash needs for a very short period of time. Cash management bills may be issued before income tax payments are received, or before the government has to make a large payment of some sort. Cash management bills range in duration from as little as four days to several months. They are issued on an as-needed basis, in contrast to a regular schedule that the Treasury follows for issuing its other bills and notes.