Karen Lynch

Already responsible for most of Aetna’s revenue, Lynch is set to take on an even greater role following CVS’s $69 billion acquisition of the company. She will preside over the health insurance side of the combined entity, guiding it through a union that could shift drug and insurance prices across America. It’s little wonder she’s being tapped: Lynch helped please shareholders with a smoother-than-expected exit from Aetna’s unprofitable Affordable Care Act business, with shares up 25% year over year.