My replies address only the method for calculating the attributable net income, not how $11,000 of excess Roth IRA contribution came to be. It's true that it's not clear where an $11,000 excess contribution would have come from. I've been operating under the assumption that these were somehow distributions from the Roth 401(k) contributions that were not eligible for rollover to the Roth IRA, but were inadvertently rolled over, or that the excess came from some entirely separate transaction(s).
