As tempting as it is, avoid recycling essays. The adcom is very old hat at this, and will smell it out instantly. And consider you a B-rate applicant who is trying to pump out applications. They want see a demonstrated interest in their program, in part, because it means you are likely to “pick” them if they “pick” you.
However, there are things you can recycle from one essay to the next, and still answer the question. Almost every school has some derivation of asking 1) why you, 2) why MBA and 3) why this school. Meaning, why should we pick you, why do you want/need an MBA, and why do you want an MBA at this school.
Why you – generally about the same for each school with regards to unique contributions you can make to the program, your value proposition. However, we also want to include what you bring to the program in terms of FIT: this relates to how you fit with their culture and share their values.
Why MBA – this story should be pretty similar from one school to the next. It needs to connect the dots between your past and future, meaning, you haven’t just pulled this idea out of the sky. However at the same time, it needs to show that you need an MBA to accomplish your goal.
Why this school – this is all about school research – leveraging the networking you have done in many forms. This part is totally unique to each school.
Make sure to answer all parts of the question. You can never recycle an entire essay, but it is possible to recycle parts of an essay.