You are confused. The SSA1099 is the document sent to you by Social Security to show the Social Security benefits you received, and it will show the Medicare premiums you paid from your SS.
Go to Federal> Wages & Income>>Retirement Plans and Social Security (SSA1099 and 1099RRB) to enter your SSA1099. (This document will not have a tax ID or payer information on it)
A 1099R is a tax document sent to you by a financial institution to show money you took from a retirement account like an IRA or 401k, or perhaps money you received from a pension as monthly pension payments. It has nothing to do with Social Security.
To enter your retirement income, Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your 1099R.