Some MBAs choosing Main Street over Wall Street

A Peace Corps-style internship program is challenging newly minted MBAs to bring their leadership and skills to America's small businesses.

MBAs Across America is a nonprofit that sent 32 MBAs on the road this summer to 26 cities to help dozens of entrepreneurs boost their businesses.

The program's founder and CEO, Casey Gerald, stumbled upon the idea while studying for his own master's degree.

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"It started with three classmates and I at Harvard Business School about a year and a half ago, not as an idea for an organization but for our lives," said the Dallas native. "Could we use our degrees, our education and our opportunity not just to make a buck but to make a difference? That question took us 8,000 miles across the country, where we spent eight weeks in eight cities working with visionary entrepreneurs."

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Sarah Calhoun, one of the pilot entrepreneurs based in White Sulfur Springs, Montana, found having a fresh pair of eyes on her business to be above and beyond her expectations.

"Knowing that there's a team of really bright, well-trained business leaders that can look at my operations and say let's try this, this and this; and I can be very open and vulnerable with them and say this is what I'm concerned about, has been helpful," said Calhoun, owner of women's workwear line Red Ants Pants. "Because when you're in the weeds of a business, it's really hard to look at that big picture."

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Those types of responses are what catapulted Gerald's social experiment into a full-blown organization that's now able to pay interns a small stipend with support from the nation's top business schools including Harvard, Stanford and Wharton. It secured corporate sponsorship from General Motors, which provided Chevy Volts for the interns' road trips, and Holiday Inn, which put up the interns in its hotels.

Gerald admitted that many of the interns so far are pursuing corporate roles after the program, but he said they're learning invaluable skills from "the most difficult internship on the face of the planet."

"This is not a consulting project. This is not just using frameworks and PowerPoint decks to help businesses," he explained. "This is a human exercise, and trust is our most important currency."

—By CNBC's Marqui Mapp