For corporate tax purposes, the I.R.S. maintains the view that a transaction between a taxpayer and a disinterested party – meaning a person that does not have an adverse interest to a taxpayer because tax neither increases nor decreases as a result of a particular term agreed upon – is not the result of arm’s length bargaining and can be disregarded where appropriate.  Now, the I.R.S. proposes to expand that approach to estate plans. The proposal is embedded in regulations issued under Code §2704. As a result, commonly used tools may no longer be available to reduce gift or estate tax.  Minority ownership discounts and unilateral governance rights that disappear at death are valuation planning tools that are at risk because of the common goals of the participants. Fanny Karaman, Stanley C. Ruchelman, and Kenneth Lobo explain.