At an event yesterday on how IRS budget cuts affect taxpayers and the tax system, agency Commissioner John Koskinen called underfunding of the agency “the most critical challenge facing the IRS today.” Commissioner Koskinen, who delivered a keynote address prior to a panel discussion hosted by the Urban-Brookings Tax Policy Center, added that “This is not just about the agency; it’s about the entire tax system.” He said that “We’re coming to a point where the significant reductions already taking place in the IRS budget are degrading the agency’s ability to deliver on its mission both during the filing season and beyond.”