If you pay the money directly to the facility, there is no dollar limit on how much you can effectively gift to benefit your mother for purposes of federal gift taxes. What’s more, this action may even entitle you to include the payment with your own medical expenses if you itemize deductions. As long as you pay more than half of your mother’s support of the year and meet certain other tests, you can treat this medical payment on behalf of your mother as your own (even if you can’t take a dependency exemption for her because her gross income is more than the allowable limit, which is $4,000 in 2015).
Debt secured by a principal residence or second home to the extent of the excess of fair market value over acquisition debt. An interest deduction is generally allowed for home equity debt up to $100,000 ($50,000 if married filing separately).