There's a lot of insurers that want a bite of a potentially lucrative Obamacare pie.
Nearly 70 percent of insurers will sell health plans on the new Obamacare exchanges by 2015—and many already plan on expanding in those markets in future years, a survey released Wednesday by professional services giant PwC's Health Research Institute found.
But even those insurers are concerned the technology that will enable people to buy coverage on those online exchanges will run into problems, the survey of 101 insurance executives found.
(Read more: Obamacare fire sale: Stripped-down plans dirt cheap)
Most insurers participating in those government-run insurance exchanges, which are set to open on Tuesday, are primarily motivated by a desire to sell plans to new members and to retain existing members, the survey said. A sense of social responsibility and public perception, while important motivators, were less of a priority.
"Our projection is for the year 2023, there will be 24 million customers in the state exchanges generating $210 billion in premium revenue annually," said Ceci Connolly, managing director of PwC's Health Research Institute.
"That's a business opportunity. Somebody is going to capture that market, and that money," Connolly said.
Those 51 exchanges in every state and Washington, D.C., are a central part of President Barack Obama's Affordable Care Act health reform plan, which mandates that individuals obtain health insurance by 2014. The exchanges will connect insurers offering a range of competing plans to individuals, who can buy at different premium amounts, often with government subsidies to offset cost.
'Strikingly high' participation
The PwC survey found that 64 percent of insurers are selling plans on the exchanges starting next month, and another 5 percent will join them by 2015. However, the degree to which those insurers participate will vary—some insurers will participate in only one or a handful of state exchanges and others will be on many more.
(Read more: 8 things about Obamacare you were afraid to ask)
About 25 percent of insurers don't plan to sell plans on the exchanges, citing concerns about profitability and worries that their plans would be swamped by enrollees who already have health needs as opposed to people less likely to seek treatment.
Still, Connolly said that overall "nearly 70 percent participation is "strikingly high."
"We heard that the ones that are going to get started in 2014 view that as the first step, and anticipate building on that in subsequent years," she said of the survey participants, who included commercial insurers, provider-owned health insurers, Medicaid-managed care insurers, third-party administrators and consumer-operated and -oriented plans.
Ten of 18 national health insurance executives said their companies would not offer plans in all state exchanges where they now do business, and 50 percent said they expect to offer plans on additional state exchanges after 2014, according to PwC.
Potential pitfall: The newly insured
One-fourth of the insurers on the exchanges are selling individual policies for the first time, and the new entrants include large hospital systems that are offering their own coverage plans.
A total of of 91 percent of executives surveyed expect premium prices to be the main factor in how people decide which plans to buy. That finding tracks other experts' beliefs about how people will select plans.
(Read more: Young do well on California, NY Obamacare exchanges)
That penny-wise mentality is not necessarily a big issue for the insurance companies that are selling the plans, Connolly said.
But, she added, "It's more of an issue for the providers"—the hospitals, clinics and doctors that will be giving the newly insured treatment under that insurance—which may have to foot some of the bill at the back end.
That's because insurance plans that have lower premiums tend to be packaged with high costs that a person must pay if they seek treatment—costs like co-pays, deductibles, co-insurance and other out-of-pocket expenses.
"People that do not fully understand how health insurance works are more likely to make coverage decisions," noted another PwC study, issued last week. "The tradeoff for low monthly premiums is typically higher pocket deductibles, which could catch people unaware after they are treated and later billed. The hospital may be forced to absorb any amount that goes unpaid. And since the patient has coverage, the hospital won't be able to apply for federal compensation."
Among the insurers selling plans on the exchanges, 63 percent said "technology integration" and 61 percent said "coordination of subsidies" were major barriers to implementing their offering on the exchanges.
(Read more: Private health exchanges set to boom)
PwC said regional subsidiaries of major national insurers may have their own IT systems that need to connect with the exchanges, which are themselves relying on a federal data hub to verify that enrollees are qualified to receive subsidies to offset plan costs.
Underestimating the risk?
According to Connolly, 34 percent of the insurers said that understanding the customers who are newly eligible to buy coverage from them was a major barrier.
"That is one area where we have some concerns," Connolly said. She said insurers might be significantly underestimating the issues they will run into dealing with a population that, on average, is less educated, more transient, and less familiar with how the health-care system works than the employees of larger companies that are the traditional recipients of insurance coverage.
That population is more apt to require interaction with the insurer than traditional clients, she said.
"Suddenly, the insurers and the providers have to deal with customers one-on-one.That's a different business model, this whole retail style of business is relatively new," Connolly said. "They're going to have to think a lot more like travel companies and retail companies that have been dealing one-on-one with customers for a lot longer."
—By CNBC's Dan Mangan. Follow him on Twitter