"I think having the private sector more deeply involved in the government programs is likely to make them better," said professor Len Nichols, the director of the Center for Health Policy Research and Ethics at George Mason University. "The public sector has learned from the private sector how to specify the conditions of the contracts with these companies."
But making a profit on the government plans can be a challenge, because the profit margins are slimmer, leaving less room for error.
Humana has been dogged by poor margins on its senior health plans this year because of high medical usage by its members. The nation's largest Medicare plan provider, which has agreed to be acquired by Aetna, expects to get a better handle on costs in the next year.
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As they become more dependent on government health-care plans, insurers also become more exposed to political risk, particularly for Medicaid, which is controlled and partly financed by state governments.
"When the economy gets tight and the politicians are looking to balance a budget, that's a natural pot of money—they're big pots of money—they look to squeeze down," said PwC's Connolly.