Can the state step in and make my Dad live in an assisted living or nursing home?

Who takes care of him now? What is your sister's role in his life?

Does he have dementia as well as Parkinson's? Has he ever been declared incompetent, or have his doctors suggested that?

Many people who can't care for themselves can get along with some in-home help. Does he have anyone coming in to help? Would he consider that?

I'm sorry this is all questions and no answers, but more detail will help all of us respond more meaningfully.

In one place you say you are living at home and the other that your dad lives alone. I'm not sure what you mean. If dad truly is alone, does he have dementia? If he isn't competent to refuse help, then you might try to get guardianship. That's a huge responsibility. If that happens, you can't keep paying sister's bills with his money. You will have to account for the money and it must go on your dad.

Is doctor should have some idea if he is able to take care of himself. You might let his doctor know he's having trouble functioning. If possible, you might try to get a person to evaluate him to see what he can and can't do. He may qualify to have someone come into the home daily to assist him with medication, bathing, etc. You might contact your local social services, senior center of Counsel on Aging. I don't know much about Parkinson,s but know it can accompany dementia. I wish you all the best. This can be very stressful.

Unless sister is living with him and helping him day to day, this is not right for her to be siphoning off his money. By "can not care for himself", do you mean the house smells like pee and poop with rotten food in the fridge, unpaid bills stacked up, any meds in total and dangerous disarray, and holes in the roof, or just not grooming as well as he used to and higher than average risk for falls? What I mean is, would Adult Protective Services agree that he is not capable of living on his own and is a danger to himself or others?