Delta Air Lines Inc. pivoted to a more-punitive approach toward getting its workforce vaccinated against Covid-19, saying unvaccinated workers will pay a $200 monthly health insurance surcharge and could lose pay protection for missing work due to the disease.

The moves reflect a new front in companies’ efforts to keep employees safe and working. Until now, many employers had used incentives, such as cash bonuses, to motivate workers to get vaccinated, or have mandated vaccinations.

Delta’s approach instead focuses on the financial burden of Covid-19 and aims to transfer it to those resisting vaccination. Studies show vaccination greatly reduces the risk of severe disease or death from the disease.

The $200 monthly charge for unvaccinated workers enrolled in Delta’s healthcare plan “will be necessary to address the financial risk the decision to not vaccinate is creating for our company,” Delta Chief Executive Ed Bastian wrote to employees Wednesday.

Mr. Bastian put a price on the lack of vaccination, saying the additional charge will help to cover hospital stays that are more likely for unvaccinated people infected with Covid-19—something that he said can cost the company as much as $50,000 a person. In recent weeks, all Delta employees who have been hospitalized with Covid-19 weren’t fully vaccinated, Mr. Bastian said.