How much of the cost to pay for living in memory care is tax deductible?

What I've done when I needed to have specific answers is to ask IRS by e-mail, and obviously save the e-mails in the event any costs are challenged or rejected by the IRS.

I don't have the IRS question e-mail address offhand, so you'd have to search at its website for it.

I would also review the statements and if the categories of charges aren't broken down, ask for a break down. Some costs may be deductible, others might not be.

Or as FF suggests, find an attorney who's familiar with elder care accounting (is that a new field yet?) and get advice from her/him.

This is a question best answered by a CPA as IRS rules are always changing.