My experience has been that, at most, you can transfer 30 credit hours from an MA program. I've seen others that cap transfer credits at 24. However, it depends on the school. I have noticed that some higher ranked programs want all the coursework to be done at their institution and don't allow any transfer credits. My advice would be to consult the handbook for each individual school.
I will add that, during one of my visits, I was told that whether or not MA coursework would count would be decided on a case-by-case basis. For example, whether my more advanced logic courses would count would be contingent on me sitting down with a professor and convincing him or her that I have a proper grasp of what should have been learned in said courses.