Do I need a POA?

YOU BETCHA you do, because when they are in the hospital and you need to talk to any creditor, you need to fax them the POA. Next you need a Health Care Proxy alongside the POA, to talk to MD's

I would AT LEAST get a healthcare POA, so in case something happens you will be cleared to speak to the Dr's, make decisions, etc. It sure has saved my butt when dad was dying, and when Mom has more problems.

If you are a signer on this account, you don't need a POA for THAT. You could need one for other things...for instance, if you need to talk to their insurance companies...like their Medicare supplements or life insurance. If they have no other assets, though, you could possibly get on without one.