I received pension checks during the year. I also received a 1099 R. Do I check the box that says The entire distribution was an RMD? Or is it not considered an RMD

Say all of it is the RMD.   If you need to start taking the RMD it will ask you if it is the RMD.  Say yes.  Anything your pension pays you is considered to be the  RMD.  Traditional pensions automatically fulfill the rules of an RMD. So for the RMD question put in the same amount as box 1.