The enacted legislation contains the 529 provision mentioned in the original post.

Yes, You Really Can Pay for Private School With 529 Plans Now
By RON LIEBER
New York Times
DEC. 21, 2017

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With 529 plans, you put money in, let it grow for years in mutual funds and then pull it out to use for higher education expenses. When you do, you don’t pay capital gains taxes on what you’ve earned over time.

Other 529 tax breaks exist, too. It is states, not the federal government, that actually administer the plans, and 35 of them offer some sort of tax deduction or credit when you deposit money. If you want to know how things work in your state, Savingforcollege.com is an excellent resource.

In what we should now refer to as the old days, you might save money for 18 years and then pull the money out over four years while a child completes college. But now, wealthy families can do what’s known as “superfunding” 529 accounts with a pile of money upfront. Then, they can pull out the $10,000 maximum each year to use for elementary and secondary school, until a child starts college. (The money will not be available for home schooling expenses, however, as that fell out of the final bill this week for technical reasons.)

Last month, Vanguard ran a scenario for me that is worth examining again to see the possibilities. At this point, it would be financial malpractice for accountants and financial advisers not to be recommending to clients that they consider this kind of upfront investment.

Imagine a wealthy family in the highest tax bracket that opens a 529 plan with $200,000 and doesn’t add another cent. The money grows at 6 percent annually, and the family takes out the maximum $10,000 each year, avoiding $2,380 in taxes annually. During the elementary and secondary school years, it saves $30,940 in taxes.

At that point, the account would still have money left over. A lot of money: $370,717. And once the beneficiary of the 529 account enters college, the family can withdraw as much as the entire annual cost of college and related expenses (not just $10,000) each year, avoiding even more capital gains taxes over that period.