UnitedHealth has debuted a lower-than-expected 2021 earnings forecast partly because of the unknown extent of COVID-19’s impact on the health care system.

The nation’s largest health insurance provider said today that it expects to take a hit in the new year from treatment and testing costs tied to the pandemic. It believes it may see more claims for things like elective surgeries that people deferred this year as the pandemic spread.

The company also cited a potential impact from rising unemployment, which can reduce employer-sponsored health insurance enrollment.

The company said it expects adjusted earnings to range from $17.75 to $18.25 per share on revenue of between $277 billion and $280 billion.

Analysts expect, on average, earnings of $18.39 per share on $278.46 billion in revenue in 2021, according to FactSet.

SVB Leerink analyst Stephen Tanal said in a research note that the initial forecast was “likely no worse than feared.”

Based in Minnetonka, Minn., UnitedHealth Group Inc. runs a health insurance business that covers about 48 million people, mostly in the United States.

Its Optum segment also runs one of the nation’s largest pharmacy benefit management operations as well as a growing number of clinics and urgent care and surgery centers.

UnitedHealth usually starts its annual forecasts conservatively, and CEO David Wichmann told analysts in October to expect that for 2021.

He said the company still has confidence in its long-term goal of 13% to 16% earnings growth, and UnitedHealth expects its underlying business to be strong.

But Wichmann also noted that the pandemic’s impact remains a big potential challenge. They still don’t know how it will affect the economy or a return to more normal levels of health care use.

Insurers like UnitedHealth reaped huge profits earlier this year when the pandemic forced patients to put off elective surgeries and other care that wasn’t deemed essential. But health insurers say those care levels have since nearly returned to normal.