If you made a conversion from a traditional to a Roth IRA, there is a good chance the entire conversion is taxable. Generally, people plan those conversions for years with low income or when the stock market is down and the IRA value at the time of the conversion is low.
If subsequent to the conversion, conditions change, such as the market drops, your income is higher than expected, you have second thoughts about the conversion, or you simply decide you can’t afford to pay the tax on the conversion, you can undo the conversion up to and including the extended due date of the return (October 15, 2012 for 2011 returns).
However, don’t wait until the last minute to make that decision, because it will require some paperwork on the part of the trustee (bank, broker, etc.).
If you have questions related to undoing a Roth IRA conversion, please give this office a call.