A 'Sneaky' Way to Save More for RetirementChoosing wisely about this particular expense can lead to healthier finances in retirement.

Which health-care choices you make come open-enrollment time could lead to healthier finances in retirement.

Health savings accounts and health reimbursement accounts, usually meant to cover short-term out-of-pocket health-care expenses, are getting more popular as companies shift health-care costs to their employees. Last year U.S. adults kept $23.8 billion across 11.8 million HSAs and HRAs, according to the Employee Benefit Research Institute—a 2,725 percent increase from 2006.

Yet for long-term retirement savings, HSAs as a stealth individual retirement account are still under the radar. "Most people don't know to ask about them," said Ed Slott, a certified public accountant and founder of IRAHelp.com. "They don't get that much attention."

The advantage is in the details. Flexible-spending accounts let users set aside up to $2,500 in pretax dollars each year for medical expenses. So do HSAs, but the scale is bigger—in 2014 a max of $3,300 for individuals and $6,550 for families, plus a $1,000 catch-up contribution for those ages 55 and older. Some of that may be free money. Companies make an average annual contribution of $500 to $749 to employees' HSAs, according to benefits firm Aon Hewitt.

Unlike the use-it-or-lose-it FSAs, leftover HSA funds roll over year after year, with tax-free investment growth. Withdrawals for medical expenses are tax-free at any age; distributions after age 65 for other purposes will be taxed at regular income-tax rates. "It has triple tax benefits like no other account," said Slott.

That's particularly valuable for health-care expenses in retirement, which can be significant. In a recent Scottrade survey, 35 percent of consumers said they were particularly concerned about health-care costs in retirement. No wonder: In 2012 the EBRI estimated that a 65-year-old man would need at least $70,000 in savings, and a woman of that age, $93,000, to have a 50 percent chance of having enough saved to cover health-care expenses in retirement.

“大多数时候,HSA的计划,这是一个no-brainer, the obvious choice," said Leslie Beck, a certified financial planner and founder of Beck Investment Management in Palo Alto, California. "The decision was made just by the economics of the medical plan."

But there are a number of qualifiers that may make health savings accounts a poor fit. For starters, they're not available to everyone who might be interested. In 2013, 47 percent of employers offered an HSA, according to Aon Hewitt, although another 34 percent said they plan to add them in coming years.

Nor are they always in budget. Health savings accounts are usually paired with high-deductible insurance plans, which offer lower premiums but require higher out-of-pocket costs before coverage kicks in. For 2014 the minimum deductible for an individual is $1,250, and for a family it's $2,500, said Slott. Maximum out-of-pocket costs on such plans are $6,350 and $12,700, respectively.

"Usually if they're using an HSA in a company plan, it's because they're high-income earners," said Beck. To use one of the accounts for retirement planning, deep pockets are practically a requirement—to max out the account annually and pay some current health-care costs without tapping the account, so the tax-advantaged assets can grow.

Whether by accident or design, consumers aren't carrying over much. In 2013 the average HSA balance was just $2,311, reports the EBRI, and the average rollover from 2012 was $1,165. Individuals who had used an account for at least five years had saved more—an average $3,491.

Even wealthier consumers, who won't have trouble hitting the max, should scrutinize investment options in health savings accounts. "Not all employers offer an option to invest those assets in a growth type of investment," said Erika Safran, a certified financial planner and founder of Safran Wealth Advisors in New York City. Most of the time, the funds are in money market accounts. "The objective of that is not long-term growth," she said. "It's long-term safety and liquidity."

When there are other investments available, commissions and other charges can eat into returns, offsetting any upfront savings from lower premiums, said Rick Kahler, a certified financial planner and founder of Kahler Financial Group in Rapid City, South Dakota. "There's not much we can control when it comes to the market, but what we can control are the taxes, transaction costs and fees," he said.

Consumers will also be better served by first maxing out plans with higher annual contribution limits—401(k)s and, for individuals, IRAs—before weighing an HSA for anything more than short-term medical needs, said Beck. "From a retirement-planning perspective, I don't consider it the first place to save money," she said.