Have you ever made non-deductible IRA contributions? Or, rolled over after-tax funds from your company plan to your IRA? If so, you will want to know about the pro-rata rule. The pro-rata rule is a rule that almost always determines the taxation of an IRA distribution when the IRA owner has any IRA containing after-tax amounts. However, some IRA distributions are not subject to the pro-rata rule. These exceptions may provide an opportunity for you to lower the tax bill that comes with an IRA distribution or conversion.