I don't think it works this way. If it's a "legitimate" expense it gets deducted from profits, so the tax rate is zero, even under today's rules. If it's not

I don't think it works this way. If it's a "legitimate" expense it gets deducted from profits, so the tax rate is zero, even under today's rules. If it's not a "legitimate" expense, e.g. a vacation paid by the company, the beneficiary gets taxed as if he got this much money in salary. The part of your list that will be taxed differently under new rules is assets - jets, boats, etc. Even so, usage of the boat for leisure should get taxed to the beneficiary at customary boat rental rates. There is room for creating accounting, as always. But it doesn't look like this is the key change here. A bigger deal is the double-taxed income. If your C Corp earns $1m, it then pays taxes at ~ 35%, with $650k left in the coffers. Then you pay yourself a dividend of $650k and you get taxed at the dividend tax rate which is also 20%, so now you have $520k left, for a combined effective tax rate of 48%. If the corp rate is cut from 35% to to 15% then your have 680k left, for a combined effective tax rate of 32%. Going from 48% to 32% is the real prize here.