The tax term for undoing the conversion and switching your funds back to a traditional IRA from a Roth is "recharacterization." You can recharacterize any amount of your original conversion, no matter your income, and for any reason. When you recharacterize the entire conversion amount, you put yourself back in the position you were in originally.
Why would you want to recharacterize? Perhaps you're now in a higher tax bracket than you expected and reconverting will reduce your income. Or maybe your investments didn't do as well as you anticipated and the value in your account has declined. Leaving the money in the new Roth means you pay tax on the original amount you converted. Recharacterizing means you save tax dollars.
Here's another beneficial recharacterization rule: You don't need to worry about being locked out of future transfers. You can reconvert the same funds to a Roth after a waiting period.
If you're considering undoing last year's Roth conversion, please call for more information. We're here to help you make the right decision.