UnitedHealth has debuted a lower-than-expected 2021 earnings forecast partly because of COVID-19’s total impact on the health care system. The nation’s largest health insurance provider said Tuesday that it expects to take a hit from treatment and testing costs tied to the ongoing pandemic. It also could see more claims for things like elective surgeries that people deferred this year as the pandemic spread. It also cited a potential impact from unemployment rates, which can hurt the company’s employer-sponsored health insurance. Aside from providing insurance, UnitedHealth also runs one of the nation’s largest pharmacy benefit management operations.