In most states, it's illegal for practices to be owned by non-MDs, and historically, only a small fraction of MDs worked for hospitals, subject to administration by businesspeople rather than doctors.
That was radically altered by private equity's entry into healthcare, with waves of consolidation that saw local hospitals merged into massive national chains, and private practices scooped up and turned into profit-maximizers, not health-maximizers:
https://prospect.org/health/2023-08-02-qa-corporate-medicine-destroys-doctors/
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