The annuity plan cost is the amount of your after-tax dollars that you (or plan owner) put into the retirement (your voluntary contributions). It is often listed in box 9b of your form 1099-R. If the information is not listed there, I recommend that you contact your annuity administrator or look into your old records. It is beneficial for you to find this, as the plan cost reduces your taxable income on the annuity distribution.
Your annuity start date is the date when you started receiving your first check (your distributions). This information is not listed on 1099-R...if you don't remember and can't find it in your records, the plan administrator should have that information.
