Room (mortgage)/Board expense as a FT employee studying FT

Hi,

 

I worked full-time as I was finishing my MS degree for the first 6 months of this year. In prior years, I transferred money from my children's 529 plans to mine and withdrew money for tuition only, but this year I wondered if I could also withdraw money to cover "room and board" -- basically paying all or part of my mortgage for those 6 months, and covering groceries.

 

What are the limits and terms for using 529 money in this way?

 

Further, I have a son in college FT living at home while he takes classes. Can any 529 money be used for his "room and board" even though he is simply living at home?

 

Thank you.