Nearly half of the women on Fortune’s Most Powerful Women in Business list are CEOs, leading and in many cases transforming their companies. Despite the record number of women CEOs on this year’s list, more than half of Fortune’s Most Powerful Women are running their companies without a Master’s of Business Administration degree.

Only 18 women on Fortune’s list of the top 50 women in business attended a business school graduate program, Fortune found after compiling the education backgrounds of 49 women on the list (Ross CEO Barbara Rentler would not disclose her education information). IBM CEO Ginni Rometty, Archer Daniels Midland CEO Pat Woertz and newly-appointed Oracle co-CEO Safra Catz are among the women on this year’s list without the degree. Some, like Catz, did opt for other professional educations in the field of law. But as the cost of a professional degree comes under more and more scrutiny, it’s worth noting that some of Fortune’s MPWs opted against one–and did just fine.

Check out Fortune’s Most Powerful Women in Business list here.

Graphic by Analee Kasudia