In 2017, in order to pay for the tax legislation in Trump's first term, a provision was added that would prevent companies from deducting Research and Development costs immediately (includes but not limited to payroll costs). It required domestic R&D costs to be expensed over 5 years (really 6 years since you only get to deduct one half of your first year expenses in the first year) and foreign expenses over 15 years (really 16 years). This provision was put in place to start January 1, 2022 because they were looking for additional revenue to pay for 2017 individual and corporate tax cuts. At the time, the thinking was it would be eventually fixed (allow for R&D deductions) as they had almost 5 years to fix the provision. Due to the politics at the time, it was not fixed. Bottom line, the political stars haven't aligned until now to actually get this fixed.