Well, anything above $5.25 million. Anything below that is *tax free*. That's a pretty sweet deal, considering how much tax you'd pay if you had to actually work for that money.
But the tax structure is only a secondary factor in the gap between the haves and the have-nots. The primary factor is that wealth accumulates in the hands of those who control the means of production, and we've let the balance between capital and labor get too far out of whack. It's only going to get worse as technology advances. As machines get more efficient, the value of human labor is diluted. The free market value of some forms of labor has already fallen below what people need to live with dignity. We need government to intervene in the economy so that the distribution is more even, if not completely equal. A cap on income and wealth might be a good thing, but I think it is more important to set a floor that no one is allowed to fall beneath.