A Roth IRA can invest in securities, usually common stocks or mutual funds. Though contributions to the Roth IRA are not deductible, any withdrawals are tax-free, as long as they are made after you reach age 59.5 and at least four years after you opened the account. Although contribution limits are the same as for traditional IRAs, eligibility may differ. If your income is too high, you are not eligible to contribute to a Roth IRA. For 2008, the caps are $101,000 and $116,000 for single returns and $159,000 and $169,000 for joint returns. If you make less than $100,000 annually, you can roll over funds from an old IRA to a Roth IRA (for tax-free withdrawals) in exchange for paying tax on the money transferred from the old IRA to the Roth. In 2010, however, anyone, regardless of income, will be allowed to convert a traditional IRA to a Roth.