How do I identify someone who will find and employ a care manager when the time is right?

Start NOW by writing out (and having notorized) the things that are important to you. That way when the time comes there is a better chance that your wishes will prevail. There is an excellent book called "Being Mortal" that covers a lot of this kind of thing -- figuring out what really, really matters to you, what makes your world go 'round, what would make the difference between wanting to live and wanting to die. What is most important in a future living situation. For my Mom -- no fish sticks (she worked as a cook, and to her, fish sticks means the cook doesn't care). For my Dad, a small workshop (though a garden might suffice). For me, I could handle almost anything except not being able to talk to people.

When the time comes, ask your MD. They are a wealth of information.
If you go on Medicaid, you will automatically have managed care.