Have a permanent residence in Washington state.. Placing my wife in a memory care facility in Idaho. What might this have to do with application for

Nothing, for now.  Memory care facilities are assisted living facilites.  They do not accept Medicaid.  However, eventually your wife may need a skilled nursing facility, which does.  Since her residence will be in Idaho, Idaho's interpretation of Medicaid rules will govern.  You might want to consult with an elder law attorney.  You can find an Idaho elder law attorney near you on the website of the National Academy of Elder Law Attorneys (www.naela.org).