The 2015 tax filing season “will be one of the most complicated filing seasons we’ve ever had,” IRS Commissioner John Koskinen said Tuesday in a keynote address to hundreds of attendees at the AICPA National Tax Conference. He also predicted that only 53% of those calling the IRS will be able to get through to an agent for help. This percentage is down from 72% a year ago (indicated as unacceptable) with an average wait time of 34 minutes.