As employers shift more health care costs toward workers, financial services firms are banking on consumer medical payments being their next big growth conduit.

The initial efforts of banks and credit card companies are focused on offering user-friendly cards tied to one of the hot trends in medical payments - health savings accounts.

Some experts say these accounts will be to today's health plans what 401(k)s were to traditional pension plans, and financial companies are trying to jump early into a market with multibillion-dollar potential.

"We think that over the next five years, the payments-processing opportunity is the most attractive for financial institutions, just looking at HSAs by themselves," said Aamer Baig, a partner at DiamondCluster International, a Chicago-based management consulting firm.

Exante Financial Services, the Minneapolis-based banking unit of UnitedHealth Group, began a test this month in Texas of a program called OnePay, which allows consumers to pay just their portion of a medical bill with a MasterCard-branded card.

It's also linked to that consumer's insurance company, so the medical service provider gets fully reimbursed the insurance company's part of the bill immediately. Consumers don't have to pay for everything upfront and wait for reimbursement checks. Exante expects the OnePay system will cut billing and other administrative costs 40 percent for insurers and 90 percent for medical service providers as well as save consumers time.

Exante isn't alone in what's currently estimated to be a $2.3 billion industry.

Columbus-based Total System Services, one of the world's largest processors of debit and credit card payments, this month inked a deal with Exante to run health payment card transactions on the TSYS network.

And American Express Co. launched its HealthPay Plus card last year in conjunction with Empire Blue Cross & Blue Shield of New York.

"Our focus is around the administrative and the financial experience for the consumer," said John Prince, Exante's chief executive officer. "There are a lot of areas on the administrative and financial sides where you could have a bad experience."

The company, which has 20 million health-related card accounts in circulation separate from the OnePay pilot, is one of the nation's largest repositories for health savings accounts, with 25 percent of the market.

These HSAs, established by consumers through a bank or credit union, are essentially savings accounts that earn interest tax-free. Like flexible spending accounts, the money in an HSA goes toward approved medical expenses.

Set amount put aside

But there's a key difference: You can only spend what's in the account.

With an FSA, you've pre-pledged a set amount to put aside, and it usually comes directly from your paycheck. Your employer will fund the account because you're paying it back a bit at a time toward your pledged amount whenever you're paid. But HSAs limit spending to what's actually in the account.

Still, many of these health savings account cards come with a line of credit - limited to health-related expenses - that is automatically triggered if your expenses exceed your HSA balance. Like regular charge cards, the credit lines charge interest, and those rates are based on your credit history.

"Consumers want a way to bridge that funding gap," said David Bonalle, vice president and general manager of advance payments at American Express. "Because the card is integrated with the health plan, we make sure the amount you get charged is the lower amount that the health plan negotiated with the health care provider."

HSAs do have their advantages. Unlike flexible spending accounts, in which the consumer forfeits any amount not used within that calendar year, HSAs roll over every year. And like FSAs, employers can contribute to HSAs in addition to employee deposits.

What's more, after they retire, consumers can withdraw money from their HSAs for any purpose and pay taxes as they would on a traditional individual retirement account.

But the Internal Revenue Service, which is responsible for some HSA guidelines, requires the consumer to enroll in a qualified, high-deductible insurance plan, at least $1,050 for single people and $2,100 for families this year. Such coverage makes HSAs more advantageous for younger, healthier people than the chronically ill.

Still, consumers are adopting them at a fast clip.

Since 2004, a year after the law creating them was enacted, financial services firms have opened more than 1 million HSAs and are establishing new accounts at a clip of about 50,000 a month, according to DiamondCluster.

By 2010, the firm expects some 15 million to 25 million HSA accounts with more than $75 billion in assets.

"Those are phenomenal numbers just for the payments business," said Phil W. Tomlinson, CEO of TSYS. "It's a huge opportunity for us long term."

If the growth trends hold up, TSYS expects that as much as 10 percent of annual revenue could come from health-care-related transactions within the next five years.

"We've been trying to make a big splash in the health market for a long time now," said Bob Borneman, health care initiatives director at TSYS Prepaid, a Total System Services subsidiary. "Our deal with UnitedHealth Group gets us in the market for a variety of different health care providers. The banks are very interested in being in the health care market because they see this as a way to offer health-related products and retain those funds."

McKinsey & Co., another consulting concern, estimates the health-care-oriented financial services market will be a $10 billion-a-year business by 2010.

That explains why several of the biggest financial services firms - including Bank of America, JPMorgan Chase and Wells Fargo, along with Exante and AmEx - are positioning themselves to divvy this growing market.

DiamondCluster's Baig, who co-authored a study on the segment this year, anticipates that by 2013, most employers will switch from defined health benefits to defined health contributions, much like they migrated from traditional pension plans to 401(k)s.

HSAs will only increase in popularity, Baig said, because employers, especially manufacturers, will be enticed by the lower costs to them.

"With high-deductible health plans, in general, the premiums on them are much lower," he said. With health care costs rising at a fast clip, big companies are looking to keep expenses down. Health care costs at troubled General Motors, for example, are about $1,500 of the price of a new car, he said.

Get-rich-quick

Financial services firms want to get in on them because it's a potentially rich revenue stream.

Banks make money through fees from each HSA card transaction, similar to debit card purchases. They also benefit from charging account management fees to employers and monthly maintenance fees of $2 to $6 to employees.

Furthermore, they can use them to cross-sell other products to HSA customers, Baig said. For example, Transamerica Financial Advisors in Los Angeles said last month it would start offering securities.