If you want to take a tax- and penalty-free withdrawal of the portion of a Roth that consists of investment earnings (amount above your initial contribution), you need to be age 59 1/2, disabled, or using the money to pay for a first-time home. However, there’s more to this rule.
The Five-Year Clock
The five-year clock doesn't start on the day you opened or funded your Roth IRA account. Rather, it starts on the first day of the tax year for which the IRA is opened and funded. This means if you funded a 2011 Roth contribution in early April 2012, your five-year clock started on January 1st, 2011. This implies you could withdraw your investment earnings free of penalty and tax, provided you meet the other criteria for Roth IRA withdrawals (you're 59 1/2, disabled, or using the money for a first-time home), as of January 1st, 2016. The five-year waiting period doesn't start again each time you make additional contributions. Using the previous example, even if you made additional contributions for the 2012 and 2013 tax years (following your initial contribution for 2011), you'll still have satisfied your five-year holding period at the beginning of 2016, because your five-year clock started at the beginning of 2011.
Unfortunately, the five-year rule gets a bit more complicated if you've gotten the assets into a Roth through converting a traditional IRA. In that case, you need to be either 59 1/2 or five years must have elapsed since your conversion for you to be able to take penalty-free withdrawals on the converted amounts on which you paid taxes at the time of conversion. Moreover, if you've converted amounts to a Roth over a period of years, each conversion amount has its own five-year holding period. The penalty will be waived if you meet certain conditions (for example, if you're using the money for qualified education or medical expenses).
Penalties and Taxes
Whether a penalty applies depends on the nature of your IRA at the time of conversion, and hinges on the Internal Revenue Service's ordering rules for distributions. If you're taking a withdrawal from a Roth, the IRS assumes that contributions are withdrawn first (always tax- and penalty-free), followed by the taxable portion of a conversion, followed by the nontaxable portion of a conversion, followed by investment earnings. For example, let’s say you had a $100,000 rollover IRA set up when you left your old firm, which you rolled into a Roth IRA in 2010. If you wanted to withdraw that money prior to age 59 1/2, you'd have to wait until 2015 to do so penalty-free. Because you owed taxes on your whole IRA amount at the time of conversion, that amount will be subject to the 10% penalty if withdrawn before five years have elapsed.
If you convert a traditional IRA that consists of nondeductible and deductible contributions, things get trickier. For example, you've built up $15,000 in a traditional IRA, $10,000 consisting of nondeductible contributions and $5,000 of deductible contributions. When converted, you'll owe tax on the $5,000 (money on which you never paid taxes). If in three years you need to withdraw $5,000, before you're 59 1/2, that amount will be subject to penalty because the IRS assumes that the amount withdrawn first is the taxable portion of your rollover, in this case, $5,000. Withdrawing the other $10,000 wouldn't trigger a penalty. Backdoor Roth IRA investors can usually avoid the 10% penalty because all or nearly all of their converted amounts will consist of money they already paid taxes on and they'll owe nothing in taxes at conversion.
Funds in a traditional IRA grow tax-deferred and are taxed at ordinary income tax rates when withdrawn. Contributions to a Roth IRA are not tax-deductible, but funds grow tax-free, and can be withdrawn tax free if assets are held for five years. A 10% federal tax penalty may apply for withdrawals prior to age 59 1/2. Please consult with a financial or tax professional for advice specific to your situation.