(FORTUNE Magazine) – Dear Annie: After about 12 years in management, I seem to have hit a plateau, especially where salary is concerned. It's been a while now since I've gotten an annual raise higher than the companywide standard of 3.5%. So I've been thinking of going to B-school. Would an MBA from a decent school get me out of this rut? -- Of Two Minds

Dear OTM: Maybe. "With the average salary of business school graduates now topping $82,000 and some elite schools boasting average graduate school salaries well into the $100,000-plus range, it may seem that getting an MBA is the ticket to financial security," observes Marc Cenedella, who runs The Ladders.com, an online job board for executives earning $100,000 or more. However, the website recently surveyed 1,521 senior executives and found that the majority (57%) believe that, to get ahead in their companies, an MBA is "nice, but not necessary." About one in four (24%) said an MBA is "very important"; 17% called the degree "unimportant."

"An MBA can be a fantastic credential, because it's not just a diploma, it's a whole network of shared experiences," Cenedella says. "But it's important for managers to focus on precisely how an MBA could further their careers. No degree can guarantee success." In other words, you need to make a long-range plan--one that covers what you hope to accomplish as well as how big a raise you'd like--and then figure out whether you really need an MBA to get there.