The technical issues associated with the launch of HealthCare.gov not only hindered enrollment, according to McDonald, it also forced insurers to spend more than expected to try to help answer customers' questions about the exchange plans.
"Many have added hundreds of new customer service representatives (WellPoint said they've hired 1,000) and beefed up customer service hours. That will cost money that the plans weren't expecting to spend," McDonald wrote.
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WellPoint CEO Joseph Swedish expressed cautious optimism about the ACA after the Obama administration reported a year-end surge in enrollment.
"We expect a similar bump in March in front of the second primary enrollment deadline," he said during an investor presentation at the JPMorgan health-care conference earlier this month.
WellPoint's Blue Cross plans have retained their dominance in the individual market in the two largest states reporting insurer enrollment data.
In California, Anthem Blue Cross garnered 31 percent of total exchange plan enrollment as of Dec. 31. In New York, Empire Blue Cross Blue Shield attracted 18 percent of total enrollment as of Dec. 24. It's not clear how many of those enrollees were previously uninsured.
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"I'm not reading too much into the initial enrollment data, because it's unclear what that really represents at this point," said Chris Rigg, health-care services analyst at Susquehanna Investment Group.
WellPoint is expected to post fourth-quarter earnings of 87 cents per share on revenue of $17.8 billion, according to FactSet analyst estimates. For 2014, analysts estimate the insurer will earn $8.35 per share on $73.41 billion in revenue.
"Their initial approach to earnings in 2014 will have a conservative bias," Rigg said.