IRS penalty
I received a letter from the IRS, stating that I understated my income on my 2017 return. It was listed as retirement income. I had no idea what it was, until I googled the name of the company and called them. It turned out to be a check from Integrity Life Insurance Company, that I thought was a life insurance payment, because my ex-husband had passed away. I thought it wasn't taxable. It was actually from an annuity he had, that I didn't know about, but I received it because he died. I moved to a new address after receiving the check. They sent a 1099-R, but I never saw it, I assume because the forwarding period had expired. I have a copy now, because I called the company listed on the letter from the IRS. I reported all of the income I knew about, from all of the tax forms I had. Now I am being charged a penalty. What course of action do you suggest?