Poor families in many states face substantial state income tax liability for the 2005 tax year. In 19 of the 42 states that levy income taxes, two-parent families of four with incomes below the federal poverty line are liable for income tax. In 16 of the 42 states, poor single-parent families of three pay income tax. And 31 of these states collect taxes from two-parent families of four with incomes just above the poverty line.