I put off taking some important classes until my senior year, should I still apply to grad school during my fall semester? I'm a junior economics major who wants to get a masters and then possibly a PhD. I know that math background is a very important component of economics grad school admissions and so I'm also minoring in math. The problem is is that I haven't taken either real analysis or an upper-level linear algebra course yet (I did take an undergrad linear algebra course over the summer and got an A in it). While I have the GPA needed to get into most masters programs and I expect to do well on the GRE, I'm afraid that my transcript as of my junior year isn't very reflective of my math abilities. During my sophomore year I was in a really bad place dealing with both anxiety and depression (I know everyone uses this excuse, but I have the doctor diagnosis to prove it) and I got a C in my calc 2 class and a B in vector calculus even though I could have gotten an A. 

Since my math background is so important for econ grad school, should I even bother applying before completing these upper-level courses that will better showcase my ability to do the math that economics grad school requires?
There are lots of programs where important classes are not taken by students until their senior year, largely because of the design of the major. Also, in most cases, if there is a "capstone" course, it's not taken until the final year, and grades would not be ready until after applications are due. However, this has not proven to be an obstacle for students applying to grad school, because the people making the decisions are cognizant of such organizations, and take this into account when making their decisions.

So don't worry too much about applying with your senior year courses missing—most of your peers will be in a similar situation!