The Internal Revenue Service’s e-file program reached a major milestone as it passed the one billion mark for individual tax returns processed since 1986, the agency said. The electronic filing program began as a pilot project in 1986 and was rolled out nationally in 1990. Prior to this year’s April 18 filing deadline, the e-file program passed another high point, as more than 100 million individual tax returns were e-filed during the 2011 filing season. Congress originally set an 80 percent goal for the electronic filing of federal tax and information returns back in 1998. More than 79 percent of taxpayers have used e-file to submit their tax returns so far this year.