OBJECTIVE: Both public (government-run), and not-for-profit (nongovernment) service providers provide alcohol and other drug (AOD) treatment services. Research has rarely studied the structural features of these providers, such as workforce characteristics, procurement arrangements, and funding security. The study reported here sought to document and analyze the differences between these two AOD treatment provider types in Australia. METHODS: The study administered an online survey instrument targeted at managers of AOD treatment sites. The survey comprised three sections: (1) the service (e.g., treatment types); (2) workforce (e.g., total number of staff); and (3) funding and procurement arrangements (e.g., contract length). The study completed a total of 207 site surveys. The studied compared government and nongovernment services on structural features that may create a more or less sustainable or vulnerable service (funding arrangements, payment mechanisms, and contract length). RESULTS: Government providers were more likely to provide medically oriented treatment types such as withdrawal management and pharmacotherapy, whereas nongovernment organization (NGO) providers were more likely to offer rehabilitation. Consistent with this, government services were more likely to employ medical professionals and nurses, indicative of a more medically oriented workforce, while NGO services were more likely to employ AOD workers, youth workers, peer workers, and counselors. Our data illustrate that NGO services were more likely to be subject to competitive tendering and to have shorter contract lengths, compared with government services, and overall to be more structurally vulnerable. CONCLUSION: Despite the reliance on NGOs to provide the majority of specialist care (71% of all treatment episodes in Australia), these services are more vulnerable than their government counterparts. To ensure that a comprehensive suite of treatment services is available, procurement arrangements that support stability and security in nongovernment service providers and government service providers are essential.