A working group of accountants formed by Novogradac sent a letter to the U.S. Treasury last month, requesting further clarification in the wake of the proposed regulations (IRS REG-115420-18) published in October.

In part, the letter states, “Taxpayer uncertainty around these issues is hindering investment in opportunity zones.”

Taxpayers must invest capital gains into opportunity zone funds by the end of 2019 if they are to reap the full tax deferral benefit of the program. But with so much uncertainty, the clock is ticking fast.

According to Financial Advisor IQ, the working group has requested guidance on the following:

• whether cash reserves held by an opportunity fund designated for investment in qualified Zone property are considered OZ property;
• whether gains realized by an opportunity fund for the sale or exchange of Zone property can be deferred if reinvested in replacement Zone property within 12 months of the sale or exchange;
• whether vacant land qualifies as Zone business property and whether substantial improvements made after Dec. 31, 2017 to property purchased before that date can be considered separate Zone business property.

Read more: New Trump Tax Shelter Needs More Detail, Experts Warn