Spurred by rising Covid cases and the Delta variant’s spread, a wave of major employers announced the same rule for unvaccinated workers this week: They will need to submit to regular surveillance testing. The new requirement raises a thorny question: Who pays for those coronavirus tests?

Doctors typically charge about $50 to $100 for the tests, so the costs of weekly testing could add up quickly. Federal law requires insurers to fully cover the tests when ordered by a health care provider, but routine workplace tests are exempt from that provision.

“It’s really up to the employer,” said Sabrina Corlette, a research professor at Georgetown University’s Center on Health Insurance Reforms. “They can require employees to pick up the tab.”