I am deducting the medical fees I paid for my mother, who is 78 and living in her own home, with my itemized medical expenses (I qualify to do this). I’m 55 years old. For 2013, do I apply the 10%- or 7.5%-of-adjusted-gross-income threshold?

Revenue ruling

A revenue ruling is the Commissioner’s “official interpretation of the interpretation of the law” and generally is binding on revenue agents and other IRS officials. Taxpayers generally may rely on published revenue rulings in determining the tax treatment of their own transactions that arise out of similar facts and circumstances.