Strong fourth-quarter results pushed shares of WellCare Health Plans (NYSE:WCG) to a new 52-week high on Thursday. Investors largely ignored the downgrades of the stock by Wachovia and Goldman Sachs, focusing more on the company's impressive earnings growth. Amerigroup (NYSE:AGP) and Molina Healthcare (NYSE:MOH), fellow providers of health-care benefits through government-sponsored programs, also reported notable increases in year-over-year earnings growth this week.

WellCare's Q4 was highlighted by a 129% increase in revenue and a 426% increase in net income versus the year-ago quarter. Membership was up 164% year over year, while the company's prescription drug plan (PDP) grew to 923,000 members. Much of this growth is attributable to strong gains made by the company's Georgia business segment, which began offering Medicaid plans in the state in mid-2006. Shareholders were also pleased to hear that WellCare's medical benefits expense ratio decreased to 78.4% of premium revenues, from 80.2% of premium revenues in its 2005 Q4.

Management remains optimistic that it can carry this momentum into subsequent quarters. The company has issued guidance indicating full-year revenue for 2007 of just less than $5 billion, and EPS in a range of $4.10 to $4.20. These numbers represent 30% revenue growth, and 21% growth in earnings over the 2006 full-year results.

The company has several growth initiatives in store to help achieve these results. Last month, WellCare began Private Fee-For-Service (PFFS) plans in 39 states, and it's already enrolled 18,000 members. The company is targeting its Georgia Medicaid and Ohio managed-care plans for increased membership in 2007, since both of these business segments came on board in the latter part of 2006. Further gains are also expected by the company's PDP business in 2007.

This stock had a great year in 2006, netting shareholders 69% in capital appreciation gains. While the gains achieved by this stock in 2007 might not be able to match those of 2006, I'm remaining bullish on this stock until the company's performance gives me reason to think otherwise.

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Fool contributor Billy Fisher does not own shares of any of the companies mentioned.