The PhD program is part time, so my wife will continue to work, and plans to return to the same role of school principal when she earns her PhD. There are program expenses, books and once a year travel requirements. We file jointly married.
The general rule is: Educational expenses to improve your current job skills are deductible. But learning a new job is not. From JK Lasser’s Your Income Tax 2013, pg 580: "For a deduction, the courses must be related to your existing job responsibilities and not lead to qualification for a new business.
This doesn't come up very often because most people come out better with the Lifetime Learning credit or tuition & fees adjustment (“above the line” deduction), rather than taking an itemized deduction subject to the 2% of AGI Threshold. But you can do both if you tuition is more than $10,000.