My mother is in an assisted living facility. Under the Healthcare Portability and Accountability Act of 1996 can she deduct her monthly living expenses?

The answer is, "It depends."  For a more detailed explanation, see this web article:

https://www.elderlawanswers.com/tax-deductions-for-assisted-living-costs-7184

I see two incorrect statements in the article that TomD8 referenced.

"Medical expenses are deductible if the expenses are more than 7.5 percent of your adjusted gross income."

If someone's medical expenses are more than 7.5% of her Adjusted Gross Income (AGI) she can claim an itemized deduction for the amount that is over 7.5% of her AGI, not for all of the medical expenses. For example, if her AGI is $60,000, 7.5% of that is $4,500. If she has $10,000 of unreimbursed medical expenses, she can claim an itemized deduction of $5,500 ($10,000 - $4,500). Only medical expenses that she pays herself, that are not paid or reimbursed by insurance, can be used to calculate the deduction. Furthermore, medical expenses are an itemized deduction. They will not reduce her tax or increase her refund unless her total itemized deductions are more than her standard deduction.

"In some circumstances, adult children may also get a tax deduction if their parents, in-laws, or other immediate family members: Live at an assisted living facility . . ."

There is no tax deduction for having a family member living in an assisted living facility. You might be able to claim your mother as a dependent on your tax return if she meets all the requirements to be your dependent. Living in an assisted living facility is not one of the requirements to be claimed as a dependent. Claiming someone as a dependent is not a tax deduction. If you claim someone other than your child as a dependent, you might get a tax credit (not a deduction) of up to $500. There are other requirements for the credit besides claiming the person as a dependent. If you can claim your mother as a dependent, whether or not you actually do claim her, she has to check the box on her tax return that indicates that someone can claim her as a dependent.

Claiming a deduction for medical expenses, and claiming someone as a dependent, are provisions of the tax law (the Internal Revenue Code). The Health Insurance Portability and Accountability Act (HIPAA) has nothing to do with these tax provisions.