Increases in medical costs of 3 to 4 percent “would be manageable by most insurers,” concluded a recent analysts at S&P Global Ratings. If costs were to go up by 10 to 12 percent, the analysts say the stress on the companies would be greater, with insurers reporting losses and forced to use their capital reserves to pay claims.

But some actuaries are predicting costs are likely to be much lower. One actuary said insurers have told him that they have no plans to raise rates sharply because the do not think the pandemic will change their predictions about ongoing medical expenses once it has run its course.

And other actuaries are coming up with estimates that are lower because they have different assumptions about how many people might be hospitalized and whether that would be offset by the declines in medical care for other illnesses or surgeries as people stay home and elective procedures are postponed indefinitely. The cost of the epidemic could be tempered if people don’t seek other kinds of care, like a routine check up or hip replacement. That also happened during the 2008 recession, when people postponed any type of care and procedures.

“We think claims are really going to drop off over the next month or two,” said Edward Kaplan, a senior vice president at Segal, which advises clients on their health benefits. He thinks his clients in New York, which is being particularly hard hit by the virus, could see additional costs of 4 to 5 percent. In other areas, if there are many fewer cases, costs could be less.

Another big unknown is whether people will be able to get treatment for Covid-19 or other illnesses, in spite of needing care. Depending on the course of the pandemic, health systems could become so overwhelmed that they have no available hospital beds or staff to treat patients who would otherwise receive care.

If patients can’t get care, overall costs could be much lower than they would otherwise be, said Trevis Parson, chief actuary for Willis Towers Watson, which advises companies on benefits. His group is estimating costs could increase by as much as 7 percent because of the pandemic.

Even then, how much the private sector will pay is unclear, especially if the government starts setting up hospital beds and temporary hospitals in various regions, and supplying staff to treat patients.