I made a repayment for several years of over payments on an annuity I receive. I have read through all the instructions on determining whether to take the credit or the deduction, but all of them seem to apply for over payments that occur within a single year. Mine is for part of 2014, all of 2015-2016, and part of 2017 and was a substantial amount of money. It seems like it may be more trouble than it's worth to go back and figure the total credit to compare the results with taking a simple deduction. Is there a general rule that applies to which cases result in a substantial difference in the results? I'm not sure I can even figure out how much of the repayment was for each of the individual years.
