You wouldn't have to report the benefits at all, if this was for an accident/health policy with Aflac, and you didn't deduct the premiums on your past income tax returns, and this wasn't a benefit paid for by your employer.
However, if you paid your premiums through your employer to a benefits plan with pre-tax dollars, or if your employer paid part or all of your premiums, some of the benefits you receive may be taxable. If both you and your employer have paid the premiums for the plan, only the amount you receive for your disability that is due to your employer’s payments is reported as income. You may receive a W-2 form from your employer the taxable amounts that received.
It was for a supplemental cancer policy. But she never had to submit a claim (thank God) and so we cashed out the policy as soon as we were able after 20 years. We did get about 2k more in the payout than we contributed. I'm going to call Aflac tomorrow to ask for a 1099-R, distribution from a insurance contract, because we never received one.