We're approaching the time of year when eager investors may start thinking of how much to fund their IRA accounts as well as 401(k) and similar plans next year.

Some others are wondering whether it still makes sense to put money into a 401(k) or a traditional IRA.

"I wish you would discuss whether tax-sheltered accounts are still beneficial at all under some scenarios," wrote Steve from Dallas. "For example, does it make sense for somebody who will retire in two years or less to put money into a 401(k) or a non-deductible IRA? I need some help in deciding what to do."

I'd start by making two immediate points. First, if you qualify for employer matching in a 401(k) plan, by all means make the contribution. To do otherwise is equivalent to refusing to accept free money. Second, your individual situation could easily contain enough variables to warrant a session with a financial planner or a certified public accountant.

Steve's question is very valid, particularly since Congress has changed the tax laws to favor long-term capital gains and dividends earned from stocks and stock funds.

At least two very good arguments exist for not continuing to put money into a tax-sheltered account:

First, long-term gains and stock dividends earned in a traditional IRA or a 401(k) plan will be taxed as ordinary income. That means the investor may keep as little as 65 percent of those earnings. The same gains and dividends, when earned in a taxable account, will be taxed at no more than 15 percent, letting the investor keep 85 percent of them.

Second, taxable accounts give investors more choice of when they pay taxes. There's no law requiring investors to sell taxable assets (and thus to incur tax liability). But traditional IRAs and 401(k) and similar plans require taxable distributions starting at age 70 1/2.

However, there are important arguments in favor of tax shelters, too.

Investing in a 401(k) is tax-deductible. That means it costs less out of pocket to save that way than in a non-deductible IRA or in a taxable account. How important that is will be different for each person.

The biggest argument for tax deferral is that it allows earnings to compound without being reduced by taxes each year. Such compounding won't make much difference in only the last two years before retirement. But in real life, the savings could easily remain invested for 10 years or more; in that case, tax-deferred compounding is quite worthwhile.

Tax-sheltered accounts also give investors maximum flexibility. Many people who are close to retirement, or already retired, may want to shift some of their assets from stock funds to bond funds. In a taxable account, doing that could trigger capital gains taxes and reduce the size of the portfolio. In a tax-sheltered account, selling stock funds and buying fixed-income funds won't affect the investor's tax bill.

Another variable that matters is whether you're investing in fixed-income funds or equity funds.

If Steve, for instance, is investing in fixed-income funds, he probably should do so in the sheltered account, because he won't lose any tax break by doing so. If he's investing in equities, he may want to skip the 401(k) and use a taxable account.

Then there's the matter of tax brackets. If Steve expects to be in a lower tax bracket after he retires, then deferring taxes could be to his advantage. Instead of paying taxes of 35 percent now (if he's in the top tax bracket), he might wind up paying only 25 percent later.

The problem is that Steve can't be certain about his future tax bracket. In a sense, he has posed a question for which the "real" right answer cannot be given.

Since I often advise investors to consult with certified public accountants on this issue, I wondered how a CPA would tackle Steve's question. To find out, we talked with Gregory Berkman, senior partner of a CPA firm in Seattle.

"I don't like to rely on a crystal ball" to predict future tax rates, Berkman said. "My crystal ball is not very good. I like to tell people to defer, defer, defer." So he would advise Steve to continue contributing to his IRA and 401(k) accounts, even with only two years until retirement.

"I like to have people contribute as long as they can," he said. Once a taxpayer passes age 59 1/2, there's no penalty for withdrawing the money from an IRA or 401(k), and that lends flexibility.

Berkman is thoroughly familiar with the argument that equity investments should be in taxable accounts in order to take advantage of the new 15 percent maximum tax rate.

"But it's not a black or white deal," he said. "A lot of it comes down to how you feel about your government and how much you trust that government not to change the rules. How confident are you that the capital gains tax will always be 15 percent?"

Berkman advises his clients to give themselves the most options and the most flexibility in retirement. He used an analogy of adjusting the temperature of water by blending just the right amount from hot and cold faucets.

"I like to see people have a blend of 401(k) assets, Roth IRAs and taxable accounts," he said. That lets a retiree mix and match withdrawals each year to "blend the perfect drink" of assets that will take the best advantage of whatever the tax laws may be.

That seems to me like very sound advice.