Can someone with an activated POA move into MI assisted living?

Are you referring to a general POA or a Durable POA? What is the exact wording in the document?

The best source for this question is probably the Michigan Elder Law agency:

https://www.elderlawofmi.org/?nowprocket=1

I've called them for advice on more than a few occasions. Typically, you would state your problem/issue/questions. A suitable Michigan attorney would be identified and would call you back. I don't recall the specific timeline, but I always had responses within a day after calling.

It also offers other services to Michigan's elderly population. It wouldn't hurt to become more familiar with these services in case they're needed.

First though, reread the document to see if it addresses terms of activation, and whether or not permission for admission to a facility is required. My gut feeling is that if the document was drafted by a qualified elder law or estate planning attorney, it will address and possibly delineate the terms for activation. But again, it depends on the terms established, and whether or not the document is Durable or not.

I have never heard of such a law re POAs so I think you must check in your own area. Any ALF should be able to answer this question for you, but an Elder Law Attorney is your best source.

There are durable POAs that become active as soon as signed, though this doesn't sound like the kind your mom has. My husband has financial POA for his brother who's in a nursing home, and their other brother has medical. NH borther is cognizant, but had trouble handling his financial affairs, taxes, sale of house, etc., so he was fine with my husband doing that. For medical, the brother with POA is consulted if anything comes up (e.g., need for specialist, change in meds) but the NH brother is free to make his own decisions. In our state, I don't believe there is any requirement that people in AL not have active POA in place. Seems odd to me. We have some ALs that are specifally memory care ALs and I assume a lot of the residents have POAs in place

I had to think about this one. I guess if a POA is active, that would mean the person has a Dementia and the ALs do not take Dementia patients. This makes sense.

You do not want to deactivate your POA. Once you do that, it can't be reassigned because Mom is not competent to reassign it. My Mom was in a small AL and I was able to place her with a POA in place. Mom needs Memory Care for people suffering from a Dementia. I don't think the not having POA in place is a law as much as it is an AL requirement. You will just need to call the ALs in your area to see what requirements they have.

I am by no means a "legal expert" but...
If you activated POA for health I am going to assume that mom is not cognizant. If that is the case then she probably should not be in Assisted Living.
If mom is cognizant how is the POA in effect? POA should be in effect only if the person can not make decisions for themselves.
If mom is not cognizant she should be in Memory Care rather than AL.
You might want to call the facilities that you are considering and ask what their protocol is.