Hi Ben

In this case, the IRS is pretty much calling the shots.

There are several "tests" to determine if an organization is eligible for 501 (c) 3 tax status. One is the publication of a magazine, another publication of a newsletter. Neither is a litimus test. If, for example, the organization holds classes on campus, or has an accredited museum, those are other "tests". The AMA happens to have neither of those, although there are a number of tests not mentioned here. The IRS site is full of information on the requirements if you are really interested.