For planning purposes, I use TurboTax to provide marginal tax impacts of various things like contributions to IRA's, withdrawal strategies, impact of qualified dividends vs. non-qualified, etc. To do this, I use my previous 1040 filing and vary parameters of interest. I like the fact that state taxes, 3.8% surcharge, etc. are handled properly. I recognize that future tax rates may change, but it is better than nothing. I believe that it would be a great enhancement to TurboTax if you had a module that would do this for you and perhaps generate graphs. For example, I generated the following to help me understand marginal rates for IRA withdrawals for my personal situation (Graph may shift and look slightly different for each individual filing situation!). I would like to see something like "vary this parameter from value A to value B in increments of X.
