Below is a *quick rough guesstimate* that gets federal + state income taxes to $360K. Many other possible ways to get there.

The maximum mortgage principal upon which the interest is deducible is 1 million dollars. Assuming 4% interest, the most he could deduct per month for mortgage interest is $3333, or $40,000 annually. That's dramatically smaller than your estimate of $322,093. (See IRS Publication 936.)

But it gets even worse because since his AGI is so high, his itemised deductions are reduced by roughly $25,000. (See Line 29 of Sch. A.)

Furthermore, since his AGI is over $374,700, he cannot claim any exemptions, so he would have 0, not 2.

You also apparently did not include Additional Medicare Tax, which would be an additional approximately $6,750 of tax on top of everything else.

The state tax estimate is also low for either NYC or California. The real average rate would be more like 11-12%.

In summary, OP's taxes seemed low to me too. The figure may be accurate, but it would involve more complicated techniques than disclosed in the above chart.

Thanks for the possible refinements.

- I'll add a max mortgage interest calc.

- itemized deduction reduction is already considered

- the 2 exemptions were already given a value of $0

- AMT already included. Multiple irritating things with this acronym, eh? The real situation probably gets hit by the other AMT as well....

- state tax estimate would be high for Texas (0%).

Other ways to get the tax down (beyond the 0% state tax) is for much of the income to be in qualified dividends, deferring a large fraction of income (457-like plan), etc. Of course we're just speculating - OP could clarify if desired.