Is the DJA's tax exception barred by the AIA?

QUESTION PRESENTED The Anti-Injunction Act (“AIA”) provides that “no suit for the purpose of restraining the assessment or collection of any tax shall be maintained in any court by any person...” 26 U.S.C. § 7421(a). The Declaratory Judgment Act (“DJA”) provides that “[i]n a case of actual controversy within its jurisdiction, except with respect to Federal taxes... any court of the United States ... may declare the rights and other legal relations of any interested party seeking such declaration.” 28 U.S.C. § 2201 (emphasis added). Federal courts have interpreted the AIA’s prohibition to be “coterminous” with the prohibition under the DJA’s tax exception. Accordingly, if a suit is not barred under the AIA, it is likewise not barred by the DJA. Cohen v. U.S., 650 F.3d 717, 730-31 (D.C. Cir. 2011) (en banc) (Kavanaugh, J.). To read the statutes otherwise—and to apply the DJA’s tax exception to bar a case that the AIA does not—would raise a “functional concern” that “defies common sense”: “[A] court would have jurisdiction to enjoin the parties appearing before it, but not to declare their rights.” Id. at 730. This case raises the following important issue: Is the DJA’s tax exception if so, does it bar a case that is not barred by the AIA? That is, In a case between two private parties that does not involve the assessment or collection of any tax—and ii where the Petitioner’s primary purpose is to recover her own property—does the DJA’s federal-tax exception deny subject-matter jurisdiction to declare the owner of a brokerage account, even though the AIA is not a bar? And if so, does the fact that Congress has not provided Petitioner with an alternative legal forum to resolve the ownership of the account give rise to an exception under this Court’s decision in South Carolina v. Regan, 465 U.S. 367 (1984)?