Participation in the wellness program at Scotts is not mandatory. In fact, under the law, such programs must be voluntary. But regulators are now trying to define what “voluntary” means.

Some hospitals require their workers get flu shots, which is controversial among those who can’t, or don’t want to get vaccines. Beyond that, there are questions about money. For example, is a big financial penalty for nonparticipation too coercive? What about incentives for completing health screenings?

Nico Pronk is chief science officer at HealthPartners, a hospital system. He researches the effectiveness of wellness programs and says their design matters.

Incentives can work, he says, but you have to be careful not to overdo it. “Once the incentive amounts go over a certain threshold, it may become a little bit more coercive,” Pronk says.