If there’s a bright spot in the recession, it’s that Americans are saving more.

Recently, the federal Commerce Department reported that people are saving 6.9 percent of their incomes, the highest level in 15 years. Not long ago the rate was zero, or less than zero, as people tapped equity in their homes to spend more than they earned.

If you are among those who have recently embraced saving, here are some guidelines on keeping your tax bills as low as possible. Money you earn is taxed at different rates depending on how you earn it.

Interest earnings, from certificates of deposit, savings accounts, money market accounts and taxable government and corporate bonds, are taxed at the same rates as ordinary income. The rate ranges from 10 to 35 percent, depending on your tax bracket.

Profits on stocks, bonds, mutual funds or other assets owned for one year or less, are taxed at the same rates as income, though it is called the short-term capital gains rate. Capital gain is the difference between the sales price and purchase price.

If the same investments are held for longer than a year before being sold, the profits are taxed at the long-term capital gains rate. That’s 15 percent for most investors, but zero for those in the 10 and 15 percent income tax brackets.

Finally, dividends, which are shares of earnings paid by stocks and stock mutual funds, are taxed at 15 percent.

Complicated enough? It gets worse.

None of these rules apply if the investment is held in a tax-deferred account such as a traditional IRA or 401(k). In that case, there is no tax until money is withdrawn in retirement, generally after you turn 59 ½.

At that point, most withdrawals are taxed at income tax rates, 10 to 35 percent. This is the case even if the profits came from long-term capital gains that would be taxed at 0 or 15 percent had the investment been held in a taxable account.

Imagine you had bought 100 shares of Google (Stock Quote: GOOG) when the company went public in 2004 at $85 a share, and that you’d sold them recently at $440. At the 15 percent capital gains rate you’d owe $5,325 tax on your $35,500 profit. Had the same transactions been done in an IRA subject to a 28 percent tax rate, you’d owe $9,940.

One final twist: There is a different type of IRA called a Roth, which allows tax-free withdrawals. You have to meet certain qualifications to have a Roth. Also, there is no tax deduction on contributions to a Roth, while there is for a 401(k) or similar retirement plan. Some investors qualify for tax deductions on contributions to traditional IRAs. Mutual fund company T.Rowe Price (Stock Quote: TROW) has a rundown, and the Roth IRA Conversion Calculator compares benefits of the two types of IRAs.

It’s easy to see why most people hate the tax system.

Savvy investors minimize taxes by putting each holding in the type of account that suits it best. Although the rules are not absolute, here are some general guidelines.

Holdings subject to income tax and short-term capital gains tax often do best in tax-favored accounts like traditional IRAs and 401(k)s.

For these holdings, such as bonds and bond funds, CDs and money markets, the tax rate will be the same as in a taxable account. But in the tax-favored account the tax will be postponed until you make withdrawals, while in a taxable account it would be owed the year the earnings are received.

On the other hand, investments subject to low tax rates often do better in taxable accounts. This is especially true of assets that will be taxed at the long-term capital gains rate.

Since that tax is not due until after the asset is sold, it can be postponed for many years. And when the tax bill is triggered, it will be at the maximum rate of 15 percent instead of the 25 to 35 percent you might pay if the asset were held in a 401(k) or traditional IRA.

—For more ways to save, spend, invest and borrow, visit MainStreet.com.