Q. My father retired from civil service in 1987. Box 2a “Taxable amount” on his form 1099-R says the taxable amount is “unknown.” My tax program asks for an amount. How do I find out what the taxable amount is?
A. Go to http://www.irs.gov/pub/irs-pdf/p721.pdf and scroll to page 5. At the top of the second column, you’ll find instructions that will guide you to the method used. However, if you go to last year’s 1040, you’ll see that he entered that figure in box 16a, “Pensions and annuities.” He then did the arithmetic needed to determine how much of it was taxable, placing that figure in box 16b. Since those numbers don’t change from year to year, you can copy them onto his 1040 for tax year 2013.