(WCG) - Get Report

posted a strong fourth-quarter profit Monday, but its shares slipped 2% in after-hours trading on weak first-quarter guidance.

For its fourth quarter ended Dec. 31, the Tampa, Fla., company earned $18 million, or 46 cents a share, up from the year-ago $6 million, or 17 cents a share. Revenue rose 42% from a year ago to $397 million.

The latest-quarter earnings were 2 cents ahead of the Wall Street estimate. Year-ago per-share figures are offered on a pro forma basis as if the company had already closed its July 2004 initial public offering.

The company said its Dec. 31 membership jumped to 747,000, reflecting 35% year-over-year growth and a 19% organic gain. The company said its Medicare expansion strategy resulted in 5% Medicare membership growth in the fourth quarter.

"We continue to grow by arranging for quality care for our members while helping to achieve cost savings for our government partners. Our strong performance in the fourth quarter was a direct result of our ability to manage effectively the healthcare needs of our Medicaid and Medicare beneficiaries in the markets we serve," said CEO Todd Farha. "During the quarter, we grew membership in all five of our Medicaid markets, a validation of the healthy partnerships we are building throughout the communities we serve."

WellCare said it expects to earn about 24 cents a share for its first quarter on revenue of $405 million or so, and $1.43-$1.50 a share on revenue of $1.7 billion for 2005. Wall Street analysts had been expecting first-quarter earnings of 32 cents a share and 2005 earnings of $1.53 a share, going by the Thomson First Call analyst consensus.

Late Monday, shares of WellCare slid 86 cents to $37.08.