We've all read that IRAs and 401(k) plans are the way to go when it comes to retirement savings, and for the most part, it's true. The tax benefits are unbeatable, your money compounds more effectively, and your employer may even give you free money for participating. So why would you put money in a traditional, taxable brokerage account?

Actually, there are a few good reasons to keep your money in a brokerage account that's not tax-advantaged. Maybe you want to save more for your retirement than your IRA allows. Maybe you want to be able to access your money at any time without paying a penalty. Or maybe you want to speculate and take some chances with your extra cash and are willing to risk a tax hit to do so. Here are a couple of situations in which a taxable brokerage account might be the way to go for your long-term savings, as well as some tips on how to use your accounts correctly.

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You've maxed out your IRA
As of the 2014 tax year, the IRA contribution limits are $5,500 per year, or $6,500 if you're age 50 or older. For a lot of people, saving that amount every year is simply not enough to be able to maintain their desired lifestyle in retirement. This is especially true for those who are not eligible to participate in an employer's retirement plan through their employer, as well as high-income individuals whose spending habits will require more than an IRA to sustain in retirement.

It is perfectly fine to put excess savings into a taxable brokerage account, but if you do so, portfolio allocation becomes important to your long-term investment returns. Specifically, to take full advantage of the tax benefits you're entitled to, you'll need to allocate your highest-yielding investments to your IRA and those that pay little or no dividends to the taxable account, where tax-free compounding isn't a big advantage anyway.

Let's say you own shares of AT&T and Google. AT&T pays about 5.3% annually, and Google doesn't pay any dividends, instead focusing on expansion and share price appreciation.

For most tax brackets, dividends are taxed at 15%. So, if a stock like AT&T is held in a taxable account, the IRS takes 15% right off the top. Therefore that amount doesn't compound year after year, essentially reducing AT&T's 5.3% yield to about 4.5%. This may not sound like much, but consider the difference this could make over a 30-year period. Here are the results of a hypothetical $10,000 investment in a stock yielding 5.3% in taxable versus non-taxable accounts. For simplicity, let's assume the share price increases by a modest 5% each year.

Dividend stock performance in taxable vs. non-taxable accounts | Create Infographics

On the other hand, with a no-dividend growth stock like Google, you don't have to pay taxes on any of your gains until you sell. So, if Google's share price grows by 12% annually, it won't matter what kind of account you hold your shares in until you sell.

Of course, this only applies to your long-term stock holdings after you've maxed out your IRA contributions. It's better to hold any stock in a tax-deferred or tax-free account, but the sting is lessened when you don't have to pay dividend tax each year.

Also bear in mind that the type of IRA you hold your stocks in plays a role as well. If your stocks are in a traditional IRA, you'll have to pay income taxes on withdrawals, but you might be able to write off your original contributions. In effect, this makes your investments cost less in the first place. A Roth IRA is the only way to really achieve tax-free growth, as all withdrawals are tax-free. However, with a Roth IRA, your contributions are not tax-deductible, and either account lets your money compound tax-free until you withdraw it.

You might have big financial needs before you reach retirement age
If you might need to make some big-ticket purchases before retirement, it might be a good idea to keep money in a taxable brokerage account.

Now, I'm not talking about college expenses. There are tax-advantaged accounts for that as well. I'm talking about buying your "forever" house or a second home somewhere between now and retirement, or accessing your money to pay potential medical expenses.

Retiring early?
One good reason to stash some of your money in a taxable brokerage account is to bridge the gap if you plan to retire early. IRA accounts and most retirement plans won't allow you to withdraw your money penalty-free until you reach 59-1/2 years of age.

Well, what if you plan to retire at 55? If this is the case, you'll need enough money for four-and-a-half years of living expenses and, hopefully, some extra for breathing room. So if you expect your annual expenses to be $70,000 during retirement, you'll want an account balance of at least $315,000 in a readily accessible account.

If you withdraw money from a traditional IRA early, not only will you get hit with taxes on your gains anyway, but you'll most likely be assessed a 10% penalty. If early retirement is a real possibility for you, it makes sense to plan ahead for it by keeping some money handy.

Other uses
There are plenty of other good uses for standard brokerage accounts, such as making investments that are too risky for your retirement savings, like speculative stocks or options. However, for your long-term savings, it's generally a good idea to make use of your tax advantages before using a regular brokerage account and to plan carefully with any investment beyond the limits of your tax-advantaged accounts. If you determine that an investment account is appropriate in your situation, use our comparison tool to learn more about online brokers.