Every single, adult, American citizen deserves the same benefits and standing as any other American adult married person receives.
Single, adult, citizens are not second class, and should not be solo'd out from receiving the exact tax and benefit standings as any other adult citizen who may choose to be married.
Most of the benefits and standing afforded married citizens in the U.S. (child custody, paternity, support, property, tax, liability and ownership) are all constantly being battled in the civil courts systems today anyway.
Stop discriminating against single adult citizens just because they may choose not to marry.