WEALTHY preparing for taxes under Clinton.

NEW YORK — Hillary Clinton is proposing higher taxes on Americans who make more than $250,000, including a 4 percent “fair share surcharge” on incomes over $5 million per year. She’s also trying to limit the ability of the rich to lower their tax bills through clever planning.

This has made the election a hot topic at accounting and advisory firms that cater to the wealthy. The election “dominates the conversations we have with clients today,” said Brian Andrew, chief investment officer at Johnson Financial Group.

Changing tax laws is easier said than done. Even if the Democratic presidential candidate defeats Republican Donald Trump, she’ll probably be negotiating any tax bills with a House of Representatives still controlled by Republicans. Democrats would get free rein to set tax policy only if a big Clinton win helps them gain control of both the Senate, which is teetering, and the House. The likeliest scenario is divided government, in which the House will thwart any substantial tax increase, said Joe Heider, founder of Cirrus Wealth Management in Cleveland.

Still, ”there’s a growing concern [among Republicans] that this could become a wave election,” Heider said.

Clinton proposes raising revenue by $1.4 trillion over the next decade. Almost all of that burden falls on the top 1 percent of taxpayers, according to the Tax Policy Center. The top 1 percent’s after-tax income would fall by an average of 7 percent. Trump, by contrast, would cut taxes by $6.2 trillion over the next 10 years, with the top 1 percent getting almost half that benefit and a 13.5 percent boost to their after-tax income.

Advisers to the wealthy are ready to take evasive action if Democrats make big gains.

“We have to be quick enough to pull the trigger after Nov. 8,” said Alan Kufeld, a certified public accountant and tax partner at PKF O’Connor Davies LLP, who says most of his clients have a net worth of $25 million to $1 billion. “You have to have a plan that is very fluid.”

The rich tend to have more financial flexibility than other taxpayers. If taxes look like they’re going up, they have a few cards they can play. One common tactic is being smart about when to receive income and when to recognize losses and take deductions. To cut the taxes you owe next April 15, for example, you can try delaying income to future years while taking as many deductions and losses as you can this year.

“If you’re going to sell something, sell it next year so you have an extra year to pay the tax,” said Richard Rampell, a certified public accountant and principal at MBAF in Palm Beach, Florida.

But a big win by Democrats could turn that conventional strategy on its head, Rampell said. Instead of trying to minimize this year’s tax bill, you might try to take as much income as possible in 2016 – for example, by selling a winning stock – rather than risk paying higher taxes on that money in 2017 or 2018.

There’s a huge question mark hanging over all these tax matters. When would any tax increase be implemented? Ordinarily, a tax bill passed in 2017 would go into effect in 2018, giving the wealthy plenty of time to prepare. The biggest fear is a tax increase passed in 2017 that’s retroactive to the beginning of the year, said Michael Kassab, chief investment officer at Calamos Wealth Management.

It’s happened before. In 1993, a tax bill passed at the beginning of Bill Clinton’s administration affected earnings that same year. If it happens again, the wealthy may have only the last several weeks of 2016 to get ready for higher taxes.

“There really is no way to know,” said Brittney Saks, a partner at PwC, based in Chicago. “It’s that uncertainty that’s making people uncomfortable.”

If Clinton gets her plan through, taxes would get both more complicated and harder to avoid. She has proposed new rates on capital gains, so that taxpayers pay higher rates if they hold an investment for less than six years. She’d also give people less flexibility to lower their tax bills with common strategies. For example, she would limit the ability of the wealthy to itemize deductions, with the exception of charitable deductions. She’d also require a minimum effective tax rate of 30 percent on incomes over $1 million — the Buffett Rule, named after billionaire investor Warren Buffett, a Clinton supporter, who declared it isn’t right that his secretary should pay a higher tax rate than he does.

But there’s good reason to wait and see what actually passes Congress.

“Even if Hillary Clinton is elected president, and even if there is a Democratic Congress, it’s not so easy to change the tax laws,” said Paul Ambrose Jr., a law partner at Cullen & Dykman LLP in Hackensack, N.J., who specializes in estate-tax planning. It might not be easy to get lawmakers, worried about their own political futures, to go along with a tax increase.

While advisers are vigilant, they’re warning clients not to make any big moves until the political future is clearer. Most of all, they say, people shouldn’t let worries about taxes override sound strategies.

“Basic economics should always drive decisions,” Heider said. “Tax benefits, or tax avoidance, should always be secondary.”