Mapes v. United States

This tax refund suit is before the court on the parties’ cross-motions for summary judgment. At issue is the constitutionality of what plaintiffs characterize the federal tax system’s "marriage penalty.” Under existing provisions of the Internal Revenue Code, some married couples incur substantially greater personal income tax liabilities than they would if unmarried and filing as single persons. Plaintiffs cohtend that this discrepancy in tax liabilities constitutes a violation of the due process notions implicit in the fifth amendment and of the equal protection standards incorporated…