A QTIP trust — Qualified Terminable Interest Property trust — is an estate planning vehicle that provides income to a surviving spouse during their lifetime while preserving the principal for beneficiaries of the deceased spouse’s choosing. It is the primary tool for balancing marital security against inheritance control in blended families and large estates. What It Is When one spouse dies, assets passing to the surviving spouse qualify for the unlimited marital deduction — no estate tax is owed on transfers between spouses at death.