How many classes can you take during a PhD?

[Cygnus_A]

So they say a PhD program is 4-6 years long, with 6 core classes during your first year (in quarters), then electives for the second year, and research after that.

Is it at all normal to take graduate courses every year of your PhD? There two many courses that I want to take in the math and physics departments. There are about 14 physics courses and 6-9 math courses that I want to take.

 

[jtbell]

When I was in grad school at Michigan 30+ years ago, I was required to take at least one course per year (i.e. every two semesters), after I completed my main coursework and achieved Ph.D. candidacy status. I'm sure I could have taken more if I had wanted to, and it didn't interfere with my research work.