Found out my sister who has POA is stealing money from my dad's account. Not sure of my course of action.

On my Moms bank statement I could acct for everything. You saw how much the AL was. Total varied because of days in a month. I still had upkeep on the house, so those bills were shown. She received a small pension a month by check. That was used on her personal items. And, I kept a record by month with receipts if there was any question. If I had to charge anything, I wrote a check to myself. Putting the check info on the receipts. Medicaid never questioned those checks.

I would ask about the withdrawls and back up to prove what they were used for Dad. If she can't do that then explain to her that POA means Dads money is for dad. She is not allowed to use it on herself. If she says she is paying herself, then explain that has to be written in the POA and what amount she can be paid. Otherwise, with no proof of what the money was spent on, she needs to return it. Tell her if Dad needs Medicaid, they will question withdrawls.

Michaelene, you will need to find proof that your sister is in fact taking money from your Dad's account. Why I say this is because Assisted Living can be expensive, on average $6k per month [varies from area to area], not counting any optional costs that can run up the cost to $10k per month.

Plus sometimes the family needs to order and deliver Depends type products and believe me, that can run up the best budgets. Cost of new clothing as one in Assisted Living usually ruin their clothes sooner than later. Some facilities charge extra for cable service and for landline phone services. I've been down that road with my own Dad and all the costs involved.

So sorry to read that your Mom had passed on. It could be that your sister took the $8k to be placed into Dad's account, since usually the spouse inherits the late spouse's assets. She could be using it for Dad's care. Thus you need to be careful before accusing her of pocketing the money

Curious, how did you find out that certain amounts were taken [or used] from the account?

I would file charges of theft from a vulnerable senior. That behavior is reprehensible and should not be overlooked or justified.

You did nothing wrong, you gave her the benefit of the doubt. She is the guilty one and should pay for being so greedy.