There was a domestic vs foreign distinction in the TCJA, passed in 2017, which took effect in 2022:

> 174 to require taxpayers to amortize specified R&E expenditures ratably over a five-year period for domestic expenditures and a 15-year period for specified R&E expenditures attributed to foreign research

https://www.journalofaccountancy.com/issues/2022/nov/amortiz...