NEW YORK (CNN/Money) - My employer matches my 401(k) contributions dollar-for-dollar up to a maximum 6 percent of salary. Currently, I contribute 7 percent of my salary and get a 6 percent match. Do you think it would make more sense for me to contribute just 6 percent to my 401(k) and put the other 1 percent in an IRA? Or should I first max out my 401(k) contributions and then consider an IRA?

-- Steve Orlich, State College, PA

Your question brings up a topic that's gotten little attention to date, but that I think will attract more and more interest in the years ahead as retiring baby boomers begin tapping into the retirement savings for regular income.

That topic is what I like to call "tax diversification," or making sure that your retirement savings aren't exposed to just one type of taxes or a single tax rate.

To understand why this topic is so important -- and how it relates to your question about how to divvy up your current savings between a 401(k) and other alternatives -- you first need to understand the full implications of contributing to your 401(k).

The main advantages of investing for retirement via a 401(K) is that the money you contribute now is excluded from taxable income, which results in an immediate tax break, plus any gains those contributions rack up compound free of taxes.

It's important to note, however, that you're not escaping taxes altogether, you're just postponing them until you withdraw the money in retirement, at which time 401(k) distributions are taxed at ordinary income rates.

At that time, you hope you'll be in a lower tax bracket, which means that you'll have avoided paying taxes at a higher rate and instead have paid them at a lower rate.

It's possible, however, that you could find yourself facing a higher tax rate in retirement. How? Several ways. If you're a really diligent saver, your withdrawals from savings could be large enough to push you into a higher tax bracket than you faced during your career.

Similarly, if you have enough income from savings and other sources during retirement, some of your Social Security benefits could also become taxable, pushing you into a higher tax bracket. Finally, there's also the chance that Congress could simply raise the tax rate on ordinary income; it's not as if our legislators haven't done this before.

In short, if all or nearly all of your retirement savings are in a 401(k), you're highly vulnerable to the tax rate on ordinary income.

But that's where an IRA can help, or, more specifically, a Roth IRA, in which you invest after tax dollars. That means you forego an immediate tax break, but you get a benefit at the back end -- i.e., your Roth money is tax free when you withdraw it.

If Congress raises tax rates when you're retired, it's no big deal as far as your Roth money is concerned. That money's not being taxed anyway. Of course, if you end up in a lower tax bracket in retirement, then you will have paid taxes at a higher tax rate than if you had put your money into a 401(k) or other tax-deferred account.

If we knew for sure which tax rate we'd face in retirement, then we'd know whether to put all our money into a tax-deferred account like a 401(k) or a tax-free account like a Roth. But most of us don't know that. There are too many variables to take into account: the deductions we qualify for, various tax credits, the whims of Congress.

Which brings us back to my theory of tax diversification. Given the uncertainty about the future tax rate we'll face, I think it's a good idea for most of us to put money into both tax-deferred accounts like 401(k)s and traditional IRAs as well as tax-free accounts like the Roth IRA.

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In addition to these two pots of money -- tax-deferred and tax-free -- I'd add another pot, namely, investments that generate long-term capital gains, which are usually taxed at lower rates than ordinary income (currently, at a max of 15 percent vs. a max of 35 percent for ordinary income).

By having money in a variety of pots, we can create income in retirement that isn't vulnerable to a single tax rate -- and we're not making an all-or-nothing bet that our future tax rate will be higher (or lower) than our tax rate during our career. In short, we're diversifying our tax exposure, just as we diversify our exposure to different asset classes when investing.

Now, getting back to your original question, I'd say this means that you should contribute in your 401(k) at least to the point where you get the maximum employer match. The match is essentially free money, and even if you end up in a higher tax bracket in retirement, the match is likely to offset that disadvantage and make the 401(k) a good deal.

Once you've gotten the employer match, though, I think it usually makes sense to fund a Roth IRA to the max. This way, you're creating a pot from which you can draw tax-free cash in retirement.

A Roth has other advantages, such as not being subject to the required minimum withdrawals I wrote about recently.

If you still have money left over after doing the Roth, then by all means throw more into your 401(k). And if you can save still more, then I'd suggest investing in stocks or stock mutual funds that generate long-term capital gains (index funds, Exchange-traded funds and tax-managed funds are good choices for this).

Pulling off the strategy I've just described assumes you're actually eligible to do a Roth IRA. (To see if that's the case, click here.)

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I should also add that you don't want to fall into the trap of scaling back your 401(k) contributions with the intention of setting up a Roth IRA and then failing to carry out your plan. If you cut back on your 401(k) and end up just spending the money, you'll have shortchanged your retirement savings.

So if you find that you somehow never get around to funding that Roth IRA, then I'd recommend just plowing all you can into your 401(k). At least then you'll have money saved for retirement, even if you end up paying more taxes on it than you'd like.

Walter Updegrave is a senior editor at MONEY Magazine and is the author of "We're Not in Kansas Anymore: Strategies for Retiring Rich in a Totally Changed World." He also answers viewers' questions on CNNfn's Money & Markets at 4:40 PM on Mondays.