My mother in law attends adult day care and pays for it herself. Can she claim the expense on her taxes?

If there may be a significant amount involved MIL can file for an extension while she finds out if she can do the deduction

rtbett, this is something that needs to be answered by a professional. With the recent U.S. Tax Reform, what was allowed previous years may not be allowed now. You could call the IRS, if you can get through since the deadline is the 17th, to ask the IRS if the expense can be used.