It's been clear for several years that trust ownership of assets would not necessarily preclude eligibility for 15-year installment payment of federal estate tax. A private letter ruling in late 1999 has provided some guidance on the issue of eligibility for a revocable living trust (a grantor trust) where the assets of the trust are used in the decedent's business.
"Trust Assets And 15-Year Year Installment Payment Of Federal Estate Tax,"
Agricultural Law Digest: Vol. 11
, Article 1.
Available at: https://lib.dr.iastate.edu/aglawdigest/vol11/iss7/1