UnitedHealth Group Inc. forecast membership in its important Medicare segment that missed Wall Street estimates, a sign of slowing growth in a business that has powered insurers’ earnings for years.

Enrollment in the company’s Medicare Advantage plans, private versions of the U.S. health program for seniors, will be less than 8.1 million next year, UnitedHealth said Wednesday in a statement. Analysts surveyed by Bloomberg had projected almost 8.4 million on average.

The shares fell as much as 1.4% in trading before U.S. markets opened. They had gained 2% this year through Tuesday’s close. 

While sales of Medicare Advantage plans have been an important source of growth and profits for health insurers, concerns about the cost to U.S. taxpayers have prompted changes that may make it less lucrative for insurers. 

Membership in UnitedHealth’s plans is expected to grow by about half a million next year.

UnitedHealth published the Medicare outlook ahead of an investor conference Wednesday in New York. Late Tuesday the company released high-level 2024 financial guidance that was broadly in-line with analysts’ expectations.

This article was provided by Bloomberg News.