Art deaccessions prompt lawsuits against museums, and some commentators advocate using the stricter trust standard of care, instead of the prevailing corporate standard (business judgment rule), to evaluate the conduct of non-profit museum boards. This Article explores the consequences of adopting the trust standard by applying it to previously unavailable deaccession policies of prominent art museums. It finds that so long as museum boards adhere to these policies, their decisions would satisfy the trust standard. This outcome illustrates an important limitation of fiduciary law: the trust standard evaluates procedural care but cannot assess deaccessions on their merits. Yet this limitation, far from undercutting the trust rule, balances judicial review with protecting boards’ management discretion. This article ventures beyond formalist analysis of fiduciary duty and examines the non-legal, substantive rules governing art deaccessions. It argues that complemented by non-legal rules, the trust standard provides the best framework for adjudicating deaccession lawsuits because it ensures judicial scrutiny of deaccession procedures while leaving appraisal of deaccessions’ merits to museum professionals and the public they serve.