In the best-case scenario, your employer offers a generous match for your 401(k) savings, and you have plenty of money left each month to fill up your IRA. You're also fabulously tanned, 20 pounds lighter, and have more hair.

But for many, reality doesn't match that happy-go-lucky fantasy. You may not even get a retirement plan at work. That makes IRA investing virtually mandatory, and it may also get you a tax deduction unavailable to other savers.

The perks of a DIY retirement
Without a workplace plan, it's up to you to make sure some of the dollars in your paycheck find their way into a retirement account. Tax laws make the task a tiny bit easier by letting married couples earn more money before snatching away the tax deduction for IRA contributions.

Consider Mr. and Mrs. Workalot. Mr. Workalot gets a 401(k) with a healthy match through his company, but his equally hardworking wife does not. Both make contributions to traditional IRAs. If the couple earns more than $83,000 ($85,000 for 2008), Mr. Workalot won't get a full deduction for his IRA contributions.

Because Mrs. Workalot doesn't have a plan at work, however, she can take a full deduction as long as the couple earns less than $156,000 ($159,000 for 2008). The deduction gets smaller as income rises, and disappears $10,000 above the limit.

The Workalot's neighbors, the Diligents, want to retire, too. Unfortunately, both Mr. and Mrs. Diligent work jobs without retirement plans. That means the Diligents can take full deductions for their total IRA contributions.

Confused? You can figure out how these rules might apply to your situation by using this IRS publication. Flip ahead to the charts on page 16 and the worksheet on page 19.

Deduct this
If you'd rather not take your tax deduction now, or you'd rather stick pins in your eyes than read an IRS manual, avoid the whole deductibility issue. Save your money in a Roth IRA instead -- both spouses can contribute the full amount as long as the couple earns $156,000 or less. No one gets a tax deduction for those deposits, but your money grows tax free. You don't have to invite an IRS agent to your retirement party, either. All the money is yours to keep.

There's another reason you might not have a retirement plan through work: You might be self-employed. In that case, look in the mirror and have a heart-to-heart chat about upgrading your benefits package. Then supplement your IRA savings with retirement accounts tailored for the self-employed.

Exercise your options
While you might lament that you're not among the lucky cubicle dwellers who have a retirement plan at work, you have something they lack -- freedom. Many 401(k) plans offer employees a pretty mediocre set of investment choices. You, as an IRA investor, can invest in pretty much anything you want. It's a great place to hold stocks and let tax deferral power up your returns.

If you're a little worried about dipping your toes into the stock market right now, let the Motley Fool CAPS community get you started. Take a look at some of the stocks they've rated with 5-star ratings -- their picks to beat the market -- and then join the discussion. Some of their current favorites include videogame retailer GameStop (NYSE: GME), Warren Buffett's Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B), and energy giant ConocoPhillips (NYSE: COP).

For more help navigating your retirement, find out:

GameStop and Berkshire Hathaway are recommendations of Motley Fool Stock Advisor. Learn more about this investing newsletter's advice and other picks for a tough market with a 30-day free trial.

Fool contributor Mary Dalrymple matches her socks, most days. She does not own stock in any company mentioned in this article, and she welcomes your feedback. The Motley Fool owns shares of Berkshire Hathaway, which is also an Inside Value recommendation. The Motley Fool has a well-coordinated disclosure policy.