Aetna is the only top-three U.S. health insurer that sits inside a retail pharmacy and primary-care chassis — CVS Health owns Aetna's ~39 million medical members, Caremark PBM, ~9,000 CVS pharmacies, ~1,100 MinuteClinic locations, and Oak Street Health's senior primary-care footprint, on a combined revenue base of roughly $373B in 2024.