As the owner of a private teaching business, Kathleen Theisen gives piano and voice lessons at students' homes in Greenwich, Conn. Business is thriving, but Theisen, who's 38 years old, is worried. She only began seriously saving for retirement three years ago. And thus far, her nest egg -- a combination of IRAs and a 403b -- has accumulated roughly $55,000.

"I feel way behind when I compare myself to my counterparts who have regular jobs," she says. "I have friends who have several hundreds of thousands of dollars."

Theisen, at least, has some money saved for retirement. There's an alarmingly large percentage of the U.S. population -- from business owners to freelancers to employees of smaller companies -- that don't have any retirement plan in place. Among the 154.7 million U.S. workers in 2005, 75 million, or 48.5%, did not have a retirement plan or pension offered to them through an employer or union, according to a report by the Employee Benefit Research Institute (EBRI). Small businesses seem to be the biggest offenders. A Department of Labor 2007 National Compensation Survey found that only 45% of small businesses (those with fewer than 100 employees) offered retirement plans to their employees.

If you're one of the millions of people without a retirement plan, don't panic. You do have options. Probably the easiest of which is to ask your employer if they'd be willing to sponsor a retirement plan at work. The answer may surprise you. "Ninety percent of the time, a small-business owner doesn't have some type of retirement plan because he or she doesn't know what's out there or no one has asked for one," says Theodore Lanzaro, managing partner at Shelton, Conn.-based Lanzaro CPA.

If that doesn't work, or if you're self-employed, then you can still plan for your golden years by choosing an alternative retirement plan. Just be sure not to put it off. The later you start, the harder it will be to rack up the savings you'll sorely need during retirement.

Going It Alone

One way to bolster your retirement nest egg is to open an individual brokerage account. When you first start putting money into the account, invest in growth stocks, which don't have tax-laden dividends to deal with, thus keeping your retirement plan tax-free until you're ready to dip into it. With these stocks and their earnings in your portfolio, the power of compounding interest and inflation will produce "unrealized growth," says Lanzaro. "If I was [in the early stages of] planning my retirement, I'd want growth at the beginning and income at the end," he says.

As you get older, rebalance your portfolio with somewhat safer value plays and sell the growth stocks. You'll incur a capital gains tax rate, but it's still lower than the income tax rate and interest that accompanies dividend stocks and bonds, respectively, says certified financial planner Elaine Morgillo. For most investments, long-term gains (for assets held more than one year) are taxed at a maximum rate of 15%, while short-term gains are taxed as ordinary income.

Of course, most people don't want to be responsible for the research that goes into picking stocks and other investments. That's why it may be best to put your money into a target-date mutual fund that is based on the year that you plan on retiring. These funds, which invest in a mix of cash, bonds and stocks, rebalance on a regular basis. As you approach your estimated retirement date, the portfolio becomes increasingly more conservative. Read our story to help you decided whether a target-date retirement fund is right for you.

Tax-Deferred Retirement Plans

The problem with going it alone is that you don't get the tax-savings that tax-deferred retirement plans such as individual retirement accounts (IRAs) provide. "For someone who doesn't have a retirement plan, an IRA is the best option," says Ray Bellucci, vice president of individual client services at TIAA-CREF. Before you open an IRA, compare fund performance and fees. "You want a company known for long-term investing and a low-cost provider," he says. "Look for...low fees which translate to higher earnings over time."

With a deductible IRA, individuals receive an upfront tax deduction on their contributions, leaving them with more money to invest. You can aggressively put money into mutual funds and you can trade stocks; the earnings, dividends, and trading profits will accumulate on a tax-deferred basis until withdrawal. And assuming your adjusted gross income (AGI) doesn't surpass the phase-out level, you can deduct your contributions.

When you withdraw money from your IRA, it'll get taxed based on your tax bracket. If you withdraw before you're 59 1/2, you'll be subject to a 10% additional tax. You may also get hit with an excise tax if you don't withdraw by the time you reach 70 1/2. Read our story to better understand the latest IRA withdrawal rules.

For those who work at a company that doesn't offer a 401(k) or pension, a tax-deductible IRA or Roth IRA may be perfect for you. For those who own or work at a small business, the SIMPLE (Savings Incentive Match Plan for Employees) IRA is typically favorable. And, for those who are self-employed or freelancers, a SEP (Simplified Employee Pensions) IRA might be the best choice. (For more, read answers to frequently asked questions about IRAs.

Here's a rundown of the IRA options:

Deductible IRAs: With a deductible IRA, singles can set aside up to $4,000 of earned income for retirement in 2007. For example, a company employee or even a teacher, who is single and makes $40,000, can contribute up to $4,000 per year from his or her salary, according to Mary Ann Greenwood, founder and president of Fayetteville, Ark.-based M.A. Greenwood & Associates. This employee receives an upfront tax deduction on his or her contribution and accumulates tax-deferred investment earnings until withdrawal. When a married couple files jointly, if neither spouse participates in a retirement plan, up to $8,000 can be deducted regardless of their AGI. For more, check out our

Roth IRAs: Roth IRAs are a great option for those who qualify. With a Roth IRA you can contribute up to $4,000 a year as long as your AGI is less than $99,000 ($156,000 for joint filers) for 2007. Partial contributions are available to individuals with incomes between $99,000 and $114,000 ($156,000 and $166,000 for joint filers). Contributions aren't deductible, but you could amass a greater nest egg because withdrawals from earnings during retirement are tax-free (as long as you're over 59 1/2 and have had the account for at least five years). In addition, Roth IRA contributions can be made at any age, whereas IRA contributions end at 70 1/2.

With both the IRA and Roth IRA, individuals who are 50 and older can contribute $5,000 for 2007. From 2008 to 2010, the standard contribution limit will rise to $5,000 per year and $6,000 for employees who are 50 and older. Read for more on Roth IRAs.

SIMPLE IRA: The best retirement plan for very small businesses is the SIMPLE IRA, says David Wray, president of the Profit Sharing/401(k) Council of America, a nonprofit association that assists companies with 401(k) plan designs, among other things. This plan, which benefits both the employer and the employees, can be established only by employers that had no more than 100 employees during the preceding calendar year, according to the IRS. Companies with these plans have an average of four employees, says Wray. "It permits very small employers to have plans for themselves as well as their workers with higher contribution rates than a typical IRA would provide," he says. This plan requires the employer to match each contribution on a dollar-for-dollar basis up to 3% of the employee's compensation, according to the IRS. For 2007, contributions are generally limited to $10,500 ($13,000 if you are 50 or older before the end of the year).

SEP IRA: To strictly fund their retirement, business owners, sole proprietors and freelancers can consider a SEP IRA, advises Bellucci. This plan is funded with tax-deductible employer contributions, and the employer must cover all eligible employees. Employee contributions are not allowed, however. SEP IRAs have higher contribution limits than the traditional IRA, are low in cost and maintenance, and don't have phase-out limits. They allow you to contribute and deduct up to 20% of self-employment income or 25% of your salary if you're an employee of your own corporation. (You can change your percentage each year without incurring any penalties.) The maximum dollar contribution is $45,000 per participant in 2007.

Variable Annuities

If you're at least 10 years from retirement, earning a high salary, and you've maxed out your IRA contributions, you may want to consider putting some extra money in variable annuities, says Michael Lanzaro, business development director, also at Lanzaro CPA. A variable annuity, which is a contract between you and an insurance company, typically offers mutual funds that invest in stocks, bonds and money market accounts. Variable annuities are tax-deferred, and there's no limit to the amount you can contribute each year. But when you withdraw your money, you'll be taxed on the earnings at ordinary income tax rates. In addition, variable annuities can carry a load of fees that can sometimes be quite pricey -- and they're risky. "If you're ultraconservative, this isn't the right product for you," says Lanzaro. For more on variable annuities, click

Clearly, employees and employers can fund their retirement in many ways without a 401(k). Theisen, for example, was hired as an adjunct professor at Western Connecticut State University this past fall. She enrolled in the state's retirement fund while continuing to contribute to her SEP and Roth IRAs. Splitting up your savings in this fashion is an ideal situation, says Morgillo who suggests that people diversify their savings across the applicable IRAs and maintain a diversified portfolio.

And as Greenwood puts it: Don't forget that saving for retirement "isn't just about getting to retirement. It's getting through retirement."