Delta Air Lines broke new ground recently by requiring unvaccinated employees to pay an extra $200 per month for company-provided health insurance. That may be a bargain for workers refusing to get vaccinated against Covid-19.

The average cost of hospitalization for Covid-19 is around $20,000, according to recently published data from the Kaiser Family Foundation. At $200 per month, it would take 100 months of added premiums, or more than 8 years’ worth, to cover the cost of a Covid hospital visit. That doesn’t cover lost worker productivity, testing and other disruptions, which is probably why Delta’s chief health officer said recently that the $200 monthly surcharge wouldn’t come close to fully covering the added costs related to unvaccinated workers.

[Read more: Vaccine mandates: Here are the companies requiring proof of inoculation from employees]

Delta (DAL) said the extra payments are meant to impose some accountability on unvaccinated workers who are raising costs and risks for everybody. Other companies could follow suit. The Food and Drug Administration’s full approval of the Pfizer Covid vaccine on Aug. 23 removes legal barriers some companies felt prevented them from requiring workers to get vaccinated, or treating unvaccinated workers differently from those who have gotten their shots. More companies are now requiring workers to get jabbed, and there’s some evidence more Americans will now be willing to get their shots.

But with about 26% of adult Americans still unvaccinated, companies are likely to be grappling with the ramifications of unprotected workers for months or years. Every unvaccinated person won’t get Covid, and every person who gets Covid won’t end up hospitalized. So every unvaccinated worker doesn’t represent a $20,000 risk. But unvaccinated workers clearly represent some higher cost of care. An obvious question for employers is whether that higher cost should be pooled among all workers, or borne directly by those choosing not to get vaccinated.

Mounting health and financial toll

Delta’s $200 per month insurance surcharge appears to be a compromise. Delta is choosing not to require current workers to get vaccinated as a condition of employment, as rival United (UAL) and many other companies are, for reasons the company hasn’t explained. It may have something to do with political opposition to vaccine mandates in Delta’s home state of Georgia. There are also questions as to whether charging some employees more for insurance complies with the Affordable Care Act, which prohibits higher insurance premiums for people with pre-existing conditions, except for narrow exceptions, such as smoking. So Delta could face a legal challenge.