@shortridge

[ US only ]
As someone who had to help his aged parents in their last few years

If possible, become an "joint owner" of all bank accounts
not sure, but joint owner with right of survivorship maybe better then joint tenant in common; the former means the money passes to you without need for will or probate

You may need 5 years (!!) of all financial documents - make sure you can get them !!

Make sure that IRS is sending you documents; it is hard to get the Power of Atty filled out