Justice Brennan, joined by Justice Marshall, agreed that the plaintiffs could not prevail in this case as presented, but he rejected the majority's standing analysis. In his view, the case should have been resolved because the plaintiffs failed to show that Revenue Ruling 69-545 actually applied to the hospitals that had affected them, not because they failed to establish Article III injury, causation, and redressability in the majority's demanding sense.
He emphasized that the ruling addressed a particular hypothetical hospital, Hospital A, and did not clearly dictate the tax treatment of every nonprofit hospital. The plaintiffs had not obtained clarification from the IRS or produced facts showing that the ruling governed the hospitals that denied them care. Their broad claim that the ruling encouraged all tax-exempt hospitals to stop serving indigent patients was therefore unripe, and their more targeted claim lacked evidentiary support at summary judgment.
Justice Brennan maintained that, if the plaintiffs had shown a connection between the ruling and the hospitals affecting them, they would have alleged a sufficient injury: harm to their opportunity and ability to obtain medical care. The alleged wrong was the Government's use of an unlawful economic incentive that induced third parties to act in ways harmful to the plaintiffs; Article III did not require proof that each hospital would certainly surrender tax benefits or that the requested relief would guarantee free or reduced-cost treatment.
He argued that the majority's approach conflicted with administrative-law standing precedents, especially Data Processing, Barlow, Sierra Club, and SCRAP. Those cases recognized standing where agency action injured plaintiffs through third-party responses or threatened future harm. By treating a difficult factual showing as a constitutional prerequisite, the Court risked insulating unlawful agency incentive programs from judicial review even when Congress had meant to protect the affected interests.