Under long-anticipated regulations published by the US Internal Revenue Service (IRS) at Section 1.482-7T,1 cost sharing arrangements (CSAs) remain effective tools that multinational taxpayers can use to efficiently develop and manage ownership of valuable intangible property among subsidiaries. Taxpayers familiar with CSAs, however, will see that valuations of pre-existing, “platform” intangibles contributed to CSAs will be scrutinized by the IRS going forward.