On November 30, 2012, the U.S. Internal Revenue Service released Proposed Regulations on the Additional Hospital Insurance Tax, more commonly known as the Additional Medicare Tax, which will apply to wages received in any tax year beginning after December 31, 2012. The Additional Medicare Tax will have a significant impact on both employers, as regards their liability to withhold on wages and other compensation, and on individual taxpayers, as regards their ultimate liability for the tax. The new tax is also likely to have an impact on tax equalization calculations for employees on international assignment.