Dyson said the cafeterias serve the companies’ interests by keeping people at work.

“They don’t want their people leaving, particularly if they have to get in cars and go find a place,” she said. “They’re gone longer. They lose time. They lose the opportunity to be in a setting where they’re talking together.”

Treasury Priorities

The Treasury Department included the issue in its list of administrative priorities for the year that started July 1. It included no deadline for completion and no detail on the content of the rules.

The project is in its preliminary stages, Erin Donar, a spokeswoman for the Treasury Department, said in an e-mailed statement.

“The application of tax rules to employer-provided meals in various contexts is an area in which additional guidance may provide useful clarity for employers,” she said.

Mark Hanson, an IRS spokesman, declined to comment. The Wall Street Journal first reported the increased IRS interest in the issue.

Free meals are common as a perk at technology companies with campuses in California. Jim Prosser, a spokesman for Twitter Inc., had no comment. Tim Drinan, a spokesman for Google, declined to comment. Vanessa Chan, a spokeswoman for Facebook Inc., said the company has no comment.

Bloomberg LP, the parent of Bloomberg News, operates pantries at its offices that often feature fresh fruit, breakfast cereal and bagels. Ty Trippet, a spokesman for Bloomberg LP, declined to comment on how the company treats the food for tax purposes.

Doughnut Exemption