Many people who ask this question can't handle the truth. Hope you're not one of them. Two points:(1) Your experience and background -- while exemplary -- are not particularly unique when it comes to McK and Bain. Not only is it typical at these firms to have high performers, it's expected. (2) Since your experience and background are merely typical, what would set you apart? Alumni network. This is where B-school comes in. If I went to Harvard, Stanford, INSEAD or LBS, why would I hire someone who didn't even bother going to B-School when there are tons of MBA graduates from my alma mater -- probably with more impressive records than yourself -- banging my door to get in? Of course, there are people without MBAs working successfully at McK and Bain. They got their foot in the door because of their contacts. In the business world, it's not just what you know, it's who you know. B-School is probably the "easiest" way for us mere mortals to get our foot in the door. Now, if your uncle happens to be a Partner at McK or Bain.....