“Sometimes I am asked when I am in Washington, ‘Why should we let rich people have this tax break?’ ” said Suzanne Goldstein Baker, a former president of the Federation of Exchange Accommodators and a lawyer with a company that helps investors swap assets. “But these rich people are the same as everyone else. And it stimulates activity for galleries, and their commissions, and auction houses and C.P.A.s and art shippers. You have a lot of people who are upstream and downstream who are ordinary working people.”

But critics say such exchanges were never intended to be a tax tool for wealthy art buyers.

“What we are seeing is yet another sophisticated federal tax avoidance scheme,” said Senator Ron Wyden of Oregon, the ranking Democrat on the Senate Finance Committee. “Some people are exploiting this tax provision as an estate planning tool to help them transfer wealth.”

In its 2016 budget, the Obama administration is proposing to eliminate the tax break for exchanges of art and other collectibles, and to limit it in other cases, like the swapping of real estate parcels. It estimates that the change could bring in $19.5 billion in deferred or avoided taxes over the next 10 years. While federal officials say they do not have a precise breakdown of the tax impact of 1031 exchanges specifically for art, the White House’s attention suggests that a sizable amount of tax revenue is at stake.

Steven M. Rosenthal, a senior fellow at the Urban-Brookings Tax Policy Center, said he agreed with the administration’s efforts. Like-kind exchanges, he said, were originally intended to avoid penalizing taxpayers whose economic situation did not change when they swapped assets. Now the exchanges have evolved into tax dodges exploited by investors, he said.

“In these days of concern over income inequality and trying to spread the burden progressively, this particular provision — especially applied to art — would provide a big bang for its buck,” he said.

There is no limit to how many times an investor can delay paying taxes through exchanges. Proponents say the exchanges are based on the principle that it is unfair to tax a “paper” gain if an investor is simply selling an asset, be it farmland or art, and quickly reinvesting the proceeds in the same kind of activity.