While I agree with your suggestion in theory, in reality it doesn't seem to work that way. I made a duplicate tax return and changed only the IRA distributions in small increments. With income on Line 7 well below the limit, the additional Fed tax is 20% of the $10K. For $20K, the additional Fed tax is 24% of the $20K and so on . My suspicion is there's more going on in the calculations than a simple 12% of ordinary income, which is why I posted the question if anyone else managed their IRA distributions with similar results.
