We have contributed to our IRA for many years (1983-present). We rolled some of this money this year to a Roth IRA since our 2020 income is less than many years due to retirement. TD Ameritrade sent us a 1099-R with our gross distribution in #1 and taxable amount in #2. In #2B it designated that the taxable amount was not determined.
How do we come up with this taxable amount? Many of the contributions to this IRA were after tax dollars. Both of us had pensions at work that did not allow us to take a credit on our taxes for contributions. Do we have to pay taxes on all of the distribution? Do we factor in cost basis from the original purchase in our taxable amount calculations?
