Without an exemption, the money could be deemed subject to the GST tax when withdrawn, says Paul Dinzeo, principal at Accredited Investors, a wealth-management firm in Edina, Minn.
"There's so much ambiguity relating to how the IRS would deal with assets put in trust for GST tax purposes this year that I see a lot of attorneys shying away from using them, " Mr. Dinzeo says.