What documentation is needed for medical deduction for AL?

The info that I got from my dad's assisted living indicated that the Room/Board portion of the bill was not deductible but, as you noted, you could take a deduction based on support with 2 or more ADL's. In my dad's assisted living the fees for ADLs are established by level - Level 1, Level 2, etc - are separately charged so you should be able to get information on which ADL's are included in their level of assistance. In my dad's case he has "Introductory level" which is medication management only, consequently he can't take any deduction.