The $21 billion managed-care company Cigna (NYSE:CI) fell a surprising 10% today, due to shockingly poor fourth-quarter earnings. While revenue did beat expectations, looking at the bottom line, the company's earnings actually fell, with net income down $45 million, to $361 million. Even after backing out one-time items, earnings per share still fell, down from $1.57 per share, to $1.39, which was a full $0.10  a share lower than Wall Street was predicting. Even worse, the company indicated 2014 would be a tough year, kicked off by a likely earnings decline in the first quarter.

However, one of the biggest points of curiosity for investors is how Cigna, and other managed care companies, will be affected by the new Affordable Care Act legislation, also known as Obamacare. In this video, Motley Fool health-care analyst David Williamson gives investors a breakdown of how Cigna has been affected so far, which insurers are benefiting from the new legislation, and how Medicare Advantage and its new reimbursement rates could hit these companies hard going forward.

David Williamson has no position in any stocks mentioned. The Motley Fool recommends WellPoint. The Motley Fool owns shares of WellPoint. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.