ROTH IRAs or 401Ks take the tax break on withdrawal, instead of when you make the investment. The crux of the bet a ROTH investment is making is that your tax rate on withdrawal may be the same or higher than your tax rate today. Most advisers assume that you withdraw less in retirement that you are making while working, and that the basic tax rate in the US will remain reasonably constant. I happen to agree with the former, but not the later. With the baby boomer retirements (damn our parents!), and issues surrounding Medicare and Medicaid in particular, I cannot see a situation where tax rates don't go up measurably for the top 5% of income earners. Note that if you make more than $100K/year today, you're in that neck of the woods.