Can my insurer deny coverage for COVID treatment because I’m unvaccinated?

Probably not. In general, your plan must make covered benefits uniformly available to similarly situated employees, and eligibility for benefits or limits on benefits cannot be based on someone's health status. The U.S. Departments of Health & Human Services and Labor have said that health plans may not discriminate against someone for benefits or coverage based on whether or not he or she obtains a COVID-19 vaccination. Note that insurers are clearly permitted to require you to meet a deductible or pay coinsurance for COVID-19 treatment. If you are hospitalized or require other high-cost services for your condition and have a high deductible or annual out-of-pocket limit, you could face significant financial liability. (45 C.F.R. §146.121; 45 C.F.R. §147.110; CMS "FAQs about ACA, HIPAA and CARES Act Implementation," Oct. 4, 2021)