An ERISA discretionary clause is a provision that provides that the plan’s administrator or claim fiduciary has the discretionary authority to interpret the terms of the plan and determine eligibility for plan benefits. In 1989, the Supreme Court of the United States issued a decision in a case called Firestone Tire & Rubber Co. v. Bruch, 489 U.S. 101 (1989), that held that claim fiduciaries receive a very deferential review of their claim determinations when a plan contain a discretionary claim. This deferential review, which is known as either the “abuse of discretion” or “arbitrary and capricious” standard of review, means that a court will not overturn an adverse claim determination if it thinks the decision is wrong. Rather, the court will only overturn the decision if it is unreasonable and unsupported by substantial evidence.