Much of the tax law passed by the U.S. Congress late last year is like an “outline of what they were thinking,” sketched out on the fly, and seriously lacking in details, according to Steven Siegel, president of The Siegel Group, a national tax consulting and estate planning firm. In addition, there are many reasons to believe the measures adopted will be reversed or changed fairly quickly, Siegel said at a special session on the new law at the Investment & Wealth Institute’s Investment Advisor Forum last week.

At the latest, changes are likely to come in 2025, when most of the measures in the bill sunset. According to Siegel, It is impossible to predict what is likely to be preserved and what changes are likely to be made at that point.

But, it’s also quite possible the code will change even sooner. Midterm elections in 2018 mean control of Congress could shift from Republicans to Democrats, and bring a raft of revisions, or outright repeal. If that doesn’t happen, or even if it does, changes could also come as a result of the 2020 presidential election.

Adding to all this uncertainty is the vagueness of the just-passed legislation itself. Even before trying to predict the longevity of various measures, individuals, businesses and their consultants will have to spend a great deal of time in the next year trying to parse the new code and get clarification as to its intentions.

Hamstrung as they may feel, individuals, businesses and their advisors cannot stand by and wait for the future to unfold, Siegel said. The measures passed have enormous implications and those wanting to safeguard their financial well-being will have to assess those implications and do the best they can to respond, even in the face of considerable uncertainty.

“You can’t stop planning,” he added.

One of the changes, for example, that some individuals can take advantage of without having to worry about future changes is the increase in exemptions for estate, generation-skipping and gift taxes. That exemption for a married couple was doubled to $11.2 million. 

Even if the exemption was to be restored to its previous level in 2020, Siegel suggested that it’s very unlikely there would be a “clawback,” i.e. that those who passed on money between 2018 and 2020 would have to pay taxes as if the smaller exclusion had been in effect. “So, using the exclusion while it’s available is good planning,” he explained.

Most of the new rules do not affect 2017 taxes and go into effect as of January 1, 2018, so planning should start now, but for the most part need not be done retroactively.

According to Siegel, one of the most difficult aspects of the law is that it defies generalizations. This is true for individuals, families and businesses.

The necessity of addressing the specifics of each individual’s or business’s situation is true in spades for the new rules for pass-through deductions for businesses, which are the most complicated of all Siegel said.

For individuals especially, one of the major changes in the law has to do with itemized deductions. While many deductions have been reduced or eliminated, such as that for state and local taxes, other rules have changed, providing opportunities for possible mitigation. And, the standard deduction has been doubled to $12,000 for an individual and $24,000 for a couple.

New tradeoffs also exist for business deductions.

While most of the new code sunsets in 2025, the corporate tax cuts do not. However, that does not mean they are permanent. It just means Congress needs to pass legislation to change them.