Today, the IRS filed a brief in the US Court of Appeals for the Ninth Circuit in Altera Corp v. Commissioner.  The brief argues that the Tax Court erred in holding that the 2003 amendments to Treas. Reg. §§ 1.482-1 and 1.482-7 are invalid to the extent they require commonly controlled parties in a qualified cost-sharing arrangement for the development of intangible property to share stock-based compensation costs.  The IRS argues that the Tax Court’s reliance on its prior opinion in Xilinx was a “fundamental error.”