Most of the key provisions of the recently passed tax bill are known, while some of the other provisions remain unknown, according to the Wills, Trusts & Estates Prof Blog in "Obscure Provision of New Tax Act Complicates Testamentary Tax Planning for Nonresidents with U.S. Beneficiaries."
The exact change in this case is not important for most people. It has to do with how stocks in foreign companies are treated after the death of a non-resident owner.
If that could impact you and your heirs, then you will want to read up on the changes. For everyone else, there is an important lesson in this.
Because the specific details of the tax cut bill are still being discovered, it is important to pay attention and not get too settled in your estate planning until every detail of the act is determined. There might be something left to discover that could have an impact on your plans.
In the end, you will want to make sure any changes you make in your estate plan account for all the changes in the new tax law.
An estate planning attorney can advise you on the impact of the new tax laws on your estate plan and recommend any necessary changes.
Reference: Wills, Trusts & Estates Prof Blog (Jan. 19, 2018) "Obscure Provision of New Tax Act Complicates Testamentary Tax Planning for Nonresidents with U.S. Beneficiaries."