In pre-ACA days, a bout with a virus might not have been considered a preexisting condition. That's because many people tend to recover quickly from viruses.

But in a blog post last week, researchers at the Rand Corp. suggested that COVID-19 could be seen differently by insurers. "Given the chronic problems [which can include organ damage, fatigue and confusion] associated with some COVID-19 cases, it is possible that some insurers would place restrictions on anyone who had a confirmed case of COVID-19," wrote Carter C. Price, Rand's senior mathematician, and Raffaele Vardavas, a mathematician at Rand who specializes in infectious disease models.

The researchers said that exclusion might also extend to people who didn't have a positive coronavirus test but did test positive for antibodies to the virus, which indicates they had it or were previously exposed.

"While a mild case of COVID-19 might not be subject to a preexisting clause, that would be up to insurers to determine," said Karen Pollitz, senior fellow, health reform and private insurance at the Kaiser Family Foundation.