Testamentary trust

A trust that does not exist until death — created under a will or by a formula in an RLT when the grantor dies. Used for staged inheritances, spendthrift protection, and bloodline control.

FacetDetail
Also calledTrust under will, sub-trust at death, children's trust
A-B / A-B-C roleBypass and QTIP are often testamentary sub-trusts of an RLT
When createdAt grantor's death
RevocableN/A — becomes irrevocable at death
Inter vivos / testamentaryTestamentary
Typical beneficiariesChildren, grandchildren, or spouse per terms
Primary purposeControl timing of distributions; creditor/divorce protection
Marital deductionOnly if structured as marital/QTIP share
Uses estate exclusionYes if funded as bypass sub-trust
In survivor's estateDepends on sub-trust type (bypass: no; QTIP: yes)
Basis step-upAt grantor's death when trust is funded
Income taxSimple or complex trust — Form 1041, K-1s to beneficiaries
Crummey powersNo (funded at death, not by lifetime gifts)
GST / dynastyMay be GST-exempt if exemption allocated on Form 706
SpendthriftCommon — limits beneficiary creditors' access
See-through (IRA)Conduit or accumulation variants possible if drafted for SECURE Act
Key tradeoffPost-death control vs ongoing trustee and 1041 compliance

These trusts matter when federal and/or Illinois estate tax is a concern. Illinois has a separate $4M exclusion that is not portable — bypass planning often matters even when federal tax is zero.