Does Contributing To 401K Reduce AGI? 
In most plans a contribution to a 401 -LRB- k -RRB- would be made with before-tax dollars . The effect is to reduce the amount of income reported . There isnt a subsequent reduction in AGI . It is possible , however , that your 401 -LRB- k -RRB- allows for after-tax contributions and a Roth option . In this situation the contributions would neither reduce the reported income nor be an adjustment on the AGI . 