Using the symbiotic sustainability model as a framework, this research investigates how many and with which businesses top nonprofit organizations report partnerships. We examined the websites of the 122 largest, most recognizable U.S. nonprofits. These websites included information about 2,418 business–nonprofit (B2N) partnerships with 1,707 unique businesses. The results suggest key differences with previous research on how U.S. Fortune 500 companies report B2N partnerships. Leading nonprofits report more B2N partnerships than U.S. Fortune 500 companies do. Furthermore, nonprofits do not maintain industry exclusivity in reporting B2N partnerships, like their business counterparts do. Finally, social issue industries do not exert the same isomorphic pressures on B2N partnerships that economic industries do. New propositions that extend the symbiotic sustainability model are presented to account for nonprofits’ unique goals for capital accumulation in B2N partnering and the industry characteristics.