When I entered an amount in box 12, letter code "W", TurboTax increased my taxable income for federal tax purposes by this amount. Why? The HSA contribution should not add to my income. In noticed in 2015, TurboTax increased my taxable income for California state tax purposes by this amount but not for federal tax purposes. Why the difference between 2015 and 2016? Is this an error in TurboTax?
