The Labor Department weighed in Monday on a question whose answer could be worth billions of dollars to gig-economy companies, deciding that one company’s workers were contractors, not employees.

As a result, the unidentified company — whose workers, it appears, clean residences — will not have to offer the federal minimum wage or overtime, or pay a share of Social Security taxes. And while the decision officially applies only to that company, legal experts said it was likely to affect a much larger portion of the industry.

The move signals the Trump administration’s approach to the way gig companies, a growing share of the economy, must treat their work force. As companies like Uber and Lyft begin to sell shares to the public, industry officials estimate that requiring them to classify their workers as employees would raise their labor costs by 20 to 30 percent.

“Today, the U.S. Department of Labor offers further insight into the nexus of current labor law and innovations in the job market,” Keith Sonderling, an official in the division that oversees such issues, said in a statement. It is a longstanding policy for the department not to disclose the names of companies receiving such letters.