Despite recognition of the importance of posttrial access to antiretroviral therapy (ART), the implementation process has not been studied. We examined whether the National Institutes of Health (NIH) guidance document was being implemented in NIH-funded ART trials conducted in developing countries between July 2005 and June 2007. All of the 18 studies we identified had posttrial access plans for trial participants. More than 70% had specific mechanisms for posttrial access, but none guaranteed long-term sponsor funding after the trials. The plans reflected variation in local contexts and the uncertainty of predicting local conditions in the long term. The strength of the NIH guidance document may be that it encourages investigators to formulate plans in advance and to work with other stakeholders to provide access to ART.