UnitedHealth Group Inc. CEO David Wichmann expressed confidence that the company's Optum division can continue to increase revenue after crossing the $100 billion revenue mark for the first time.

Amid a competitive environment for pharmacy benefit managers, Optum brought in $101.28 billion in revenue for full year 2018, a year-over-year rise of 11.1%. Wichmann said the company views Optum as a product that goes beyond "the traditional PBM."

"We work with and deeply respect the new and emerging competition," Wichmann said. "We're not going to underestimate it, but we also remain highly confident in our own capacity to compete and continue to grow and manage our business."

CFO John Rex said that although revenue and prescription would be affected by the loss of Cigna Holding Co.'s book of business after the competitor acquired Express Scripts Holding Co., the earnings outlook for the year would not be. Rex also noted that the timing for the transition "isn't completely certain yet."

Wichmann also reiterated that UnitedHealth is advocating for a repeal or deferral of the federal health insurance fee, which has been suspended for 2019 but is expected to return in 2020. He said the tax would raise premiums by $500 a year for the average senior couple and by roughly $480 for families with small business coverage.

"We can't comment or speculate on the outcome, but we would take this opportunity to applaud the bipartisan action that has occurred across Congress," Wichmann said. "Hopefully we'll get this taken off the consumer."