The United States Supreme Court case, United States v. Jicarilla Apache Nation (2010), revolved around the issue of whether a fiduciary exception to attorney-client privilege applies to the general trust relationship between the U.S. government and Indian tribes. The Jicarilla Apache Nation had filed a claim against the U.S., alleging that it mismanaged funds held in trust for them from natural resource exploitation on tribal land. During discovery, they sought access to legal advice given by Department of Interior attorneys about managing these assets but were denied due to attorney-client privilege claims by the U.S.. The court ruled 7-1 in favor of the United States, stating that no such fiduciary exception existed under federal common law or statutes governing this specific type of trustee-beneficiary relationship with Native American tribes.

In the dissenting opinion for United States v. Jicarilla Apache Nation, Justice Sotomayor argued that the majority's decision was a departure from established trust law principles and federal Indian policy. She contended that when the U.S manages funds on behalf of Native American tribes, it acts as a trustee with fiduciary duties to its beneficiaries - including an obligation to share relevant information about how those assets are managed. The majority's ruling denied this right to access such information by invoking attorney-client privilege on behalf of the government, which she believed undermined tribal sovereignty and self-determination. Furthermore, she pointed out inconsistencies in applying common-law trust doctrines selectively while ignoring others without any clear rationale or precedent.