That's where flexibility will help retirees and companies save money. Instead of being covered by a company plan that provides the same coverage to all participants, companies are providing their retirees with a health reimbursement account that allows them to use the money to pick the coverage they want. However, these health reimbursement accounts set the rules for how the money can be spent.

The question for companies, Spencer said, is, "How do you give greater choice while capping expenditures?"

David Embry, president of SelectQuote Benefit Solutions of Kansas City, Mo., which operates full-service insurance exchanges, works with companies to provide choice and keeping costs down.

"What you're seeing, "he said, "is that in the past, employers provided health insurance through group plans.  Now, for balance sheet reasons, many firms are getting out of group plans and moving to giving lump sums."

"In our client space," Spencer said, "many are talking about exchanges."

Embry forecast that in 2014, more companies would make the move. He said that with increased choice offered by health care exchanges, plan participants would have quality, competitive alternatives to consider as they plan for retirement. Embry said additional benefits, such as dental and vision offerings and even coverage directed at specific diseases like cancer would also become more available at exchanges next year.

"One size fits all just doesn't work anymore," Embry said. "Everyone's situation is different. I think in all benefits companies will evolve to choice."

Keeping benefits costs down is important for both employers and employees. Exchanges, Embry said, can help do that.

"Competition is going to keep costs down," he said.

Both Embry and Spencer said the flexibility allows retirees to purchase the coverage they want. However, with the change in benefits comes the need for employee education.

Embry said his company helps by sponsoring employee meetings, providing booklets and incorporating information into employer benefits information.

It also means that for many retirees, they'll have to navigate Medicare Advantage and Medicare supplemental policies.

But Spencer cautions that when it comes to calculating retirement one aspect is ignored.

"Generally, when retirees look at retirement planning they aren't thinking about health care," he said.

An AARP survey showed just how little attention is paid to the matter. Just 36 percent of those 50 to 64 said they had tried to estimate how much they would need to save to cover retirement heath care costs. Just 16 percent said they were very confident they would have enough saved to pay for health care.

Part of the problem, AARP concluded, is that many adults think Medicare pays for more of health care needs that it does. The costs of premiums for drug coverage (Medicare Part D) and other policies can add up. Then there's the need for supplemental insurance that pays for out of pocket expenses that Medicare doesn't cover.

And while Fidelity estimates that a couple retiring this year at age 65 would need $220,000 to cover their medical expenses, nearly half of those responding (42 percent) to the AARP survey thought $100,000 would be enough. Another 16 percent said $50,000 would be adequate.

Still unknown, however, is how much a company saves by moving retirees to exchanges is difficult to assess.

"Savings can be significant," said Spencer. "It depends on plan design."

Curcio Webb, which focuses on providing services to large companies, helps them find the best health exchange company to partner with. Spencer said the company can provide an independent voice because it never takes money from insurance providers.

When a firm like SelectQuote Benefit Solutions is matched with a company, it finds the right insurer for the employer and then helps educate plan participants about their options.

"Ultimately, it's about treating your employees with compassion and care," Spencer said.