Lawmakers on Capitol Hill will start the new year with momentum on major tax reform proposals — including a provision that could pose a financial hardship for large law firms and hit partners with outsized tax bills.

Senate Finance Committee Chairman Max Baucus (D-Mont.) this month expects to receive public comments on draft legislation that would mark a fundamental change to the way large law firms and other professional service firms report and pay their taxes. A similar provision was included in a draft bill first circulated in March by Rep. Dave Camp (R-Mich.), chairman of the House Ways and Means Committee. Camp has called America’s tax system “broken.”