By 2015, half the US population living with human immunodeficiency virus (HIV) infection will be older than 50 years of age. As antiretroviral therapy (ART) coverage continues to expand worldwide, this aging of the HIV epidemic will be mirrored in developing countries. In sub-Saharan Africa, ART has already reduced mortality rates, with 320,000 (or 20%) fewer people dying of HIV-related causes in 2009 than in 2004. 1 Currently, HIV-infected Ugandans in their 40s who are receiving ART can expect to live well into their 60s. 2 The increased life expectancy of HIV-infected persons will lead to increases in HIV prevalence among older adults. Approximately 1 in 8 HIV-infected adults and 1 in 10 patients receiving ART in sub-Saharan Africa are older than 50 years of age, 3 and these ratios are likely to increase manyfold in the coming decades (see maps). Yet the world is unprepared to deal with an aging population with HIV. We are still learning about what determines the success of ART in older age groups, and our understanding of the future needs with regard to treatment for chronic noncommunicable diseases, such as cardiovascular disease and diabetes, in older HIV-infected adults in developing countries is very limited. To date, the focus of the global response to HIV has been on providing care to mothers, children, and the most severely immunocompromised patients. The June 2011 United Nations High-Level Meeting on AIDS emphasized the integration of HIV services with maternal and child health services but neglected the emerging evidence on the aging of the HIV epidemic. Similarly, the September 2011 United Nations High-Level Meeting on Non-Communicable Diseases did not consider the effect of the large-scale provision of ART in developing countries on the age distribution of the population and the future global need for the treatment of noncommunicable diseases. The failure of both meetings to consider the issue of HIV and aging underscores how little attention is being paid to this coming challenge. Effectively addressing the needs of aging HIV-infected populations will require political will, strengthened health systems, a greater commitment of human resources, and improved clinical infrastructure and expertise. Political will is needed to put the aging of the epidemic on political agendas worldwide, just as it was necessary before 2004 to mobilize governments and donors to commit to improving access to ART. Political pressure helped drive down the price of ART from more than $10,000 to less than $100 per person per year. Similar action could help address the current high cost of drugs for diseases occurring late in life, including many cancers and end-stage organ diseases such as congestive heart failure and renal failure.