Echoing the posts above. Would also say having pre-doctoral research experience gives you a leg up during the increasingly competitive application process. Here is a link to MIT Sloan predoc opportunities: https://mitsloan.mit.edu/programs/phd/mit-sloan-predoctoral-opportunities
I applied 3 years ago while working full time only to 4 schools and got rejected from all of them. This year, got into my dream school after applying again with a MA degree and pre-doc experience at a leading business school. Don't lose hope!
