Can someone with experience provide information on what the process is to amend a MFJ to MFS.   2021 return was filed as MFJ.  There is a benefit if it were filed as MFS.  IS a 1040x involved?  How do you then file the separate returns?  I am using ProSeries Pro.  Appreciate any information you can provide. 

While researching the topic, I thought I read a return filed as MFJ CANNOT be changed to MFS after the due date.  Is that correct?