This Article uncovers and names a phenomenon of pressing importance for healthcare policy and religious liberty law: the rise of zombie religious institutions—organizations that have contractual commitments to religious identity but lack actual attachments to churches or associations of religious people. Contracts create religion—sometimes in perpetuity—for institutions that are not, or never have been, religious and for providers who do not share the institution’s religious precepts. This Article details religion’s spread across healthcare through affiliations, mergers, and—most surprisingly—sales of hospitals that continue religious practice after their connection to a church ends. These contracts require hospitals—secular and religious, public and private, for-profit and nonprofit—to comply with religious tenets. “Religious” institutions far removed from the paradigm of the church populate the marketplace. In this way, private law impedes public policy, expanding the universe of institutions eligible for religious exemption from otherwise applicable laws. Moreover, as the category of religious institution loses its specialness, theories of religious institutionalism founder. The presumption of autonomy of religious institutions from regulation cannot survive in the marketplace where religious identity can be bought and sold.