Well, yes, @Jack from Ohio - but there are also times we need to plan *anyway*. New baby, someone who expects their s-corp to do way better in 2017 (maybe they have a signed contract with payment schedule), maybe they inherited dad's mutual funds and know roughly how much more in dividends and interest to expect, get laid off mid-summer and severance package runs through end of September... and folks want to make sure they won't have a huge bill next April. All we can do is our best, with caveats about changes to come. But we still have to help with the planning.