Is Box 12, letter code "W" amount considered taxable income?

[smclean3]

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?

[Opus 17]

Code W is your HSA contributions.  It will be considered taxable until you complete the HSA section on the deductions and credits page to show that you had the right kind of insurance to be eligible to make HSA contributions.

[f-yocum]

i completed the hsa section and it is still showing it as taxable.  should he deduction show up on 1040 line 25

[Opus 17]

Line 25 only applies to amounts that you contribute after tax not by payroll deduction.  Amounts contributed by payroll deduction are not included in your taxable box 1 income in the first place.  It's not an additional deduction because it was never taxed in the first place.

(It may be taxed if your contributions are not qualified. Then it would be Other Income on line 21.)