The type of project or projects that are funded by a bond affects the taxability of income received on the bonds held by bond holders. Interest earnings on bonds that fund projects that are constructed for the public good are generally exempt from federal income tax, while interest earnings on bonds issued to fund projects partly or wholly benefiting only private parties, sometimes referred to as private activity bonds, may be subject to federal income tax. However, qualified private activity bonds, whether issued by a governmental unit or private entity, are exempt from federal taxes because the bonds are financing services or facilities that, while meeting the private activity tests, are needed by a government.