That's got to be frustrating for management.

Health insurance giant UnitedHealth Group (NYSE:UNH) beat analysts estimates by a whopping 11% -- and its stock fell 4% yesterday. That's right: The stock fell 4%.

Then again, management couldn't have expected much more. Wall Street is a "what will you do for me tomorrow?" kind of place, and management stuck with its rather paltry guidance for 2010. This year the company expects to make $2.90 to $3.10 per share, down from the $3.24 that it registered last year.

CEO Stephen Hemsley even went so far as to say that analysts' estimates for the first quarter are too high. The company is still dealing with a high unemployment rate, which is a double whammy. It lowers enrollment in its profitable commercial business, and it increases the number of people on COBRA, who tend to be high users of medical services. UnitedHealth is also expecting lower payments from government plans to put pressure on the bottom line.

Of course, this earnings season, health insurers including Aetna (NYSE:AET), Humana (NYSE:HUM), WellPoint (NYSE:WLP), and Cigna (NYSE:CI) are likely to trade more on the whims of politicians than on financial fundamentals, now that the future of health-care reform seems less certain. We may have seen some of that yesterday with UnitedHealth's decline. House Speaker Nancy Pelosi said the House didn't have enough votes to pass the Senate version as is, which would have benefited health insurers, since the Senate's version doesn't include a government-sponsored public option that would compete with private insurers.

Trading at 11 times the middle of next year's earnings, UnitedHealth isn't as cheap as it's been in the past, but it's not particularly expensive, either. Investors that can ride through the tough year -- perhaps using a covered-call strategy to boost the return -- should see the insurer improve once the jobs come back.

UnitedHealth and WellPoint are Motley Fool Inside Value picks. UnitedHealth is a Motley Fool Stock Advisor recommendation. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool owns shares of UnitedHealth Group and has a disclosure policy.