Some impact investors — whose aim is to make money while funding projects that bring about social or economic benefits — are targeting their funds toward areas in the Southeast and industrial Midwest. And several impact investors are working with philanthropists to try to establish accountability standards for the funds that the federal government does not yet require, to address issues like the quality of jobs created in poor areas. The goal for impact investors in opportunity funds is to steer money to small businesses and other development that communities actually need, and not just to finance things that provide wealthy investors with the highest returns, like high-end hotels or condos.

“I believe it really can be a great model to demonstrate the holistic, community-informed investments that can transform these distressed communities, while earning returns,” said Jim Sorenson, an entrepreneur based in Utah. Mr. Sorenson, who hosts an annual gathering of impact investors in Salt Lake City, devoted much of this year’s meeting, in February, to discussing the potential benefits of the zones. He joined several groups in announcing an effort to create a “guiding set of principles” for making such investments.

Fran Seegull, the executive director of the U.S. Impact Investing Alliance and a conference attendee, emphasized the importance of laying out such principles early.

“First movers will really shape the market,” Ms. Seegull said. “Those of us that care about community engagement, community solutions and metrics feel that it’s important to set the tone” for other investors.

The concept of opportunity-zone funds is also captivating Wall Street. Its inclusion in the tax law was celebrated by some big technology investors seeking ways to capitalize on stock market winnings while keeping their tax bills low.