Background: In 2005, the resources needed to support orphans and vulnerable children in sub-Saharan Africa were estimated at US$1.1–4.1 billion. Approaches to support vulnerable children have changed considerably since then. This study updates previous estimates by including new types of support and information on support costs. Methods: We considered 16 types of support categorized as economic strengthening, education support, social care and community outreach, and program support. The estimates combine the number of children in need of each intervention with unit costs derived from the literature and coverage goals based on current coverage and feasible future improvements. Results: The number of children affected by AIDS in low- and middle-income countries varies from 58 million to 315 million depending on the definition of need. The resources required to provide support to children living in poor households will grow from US$ 4.2 billion in 2012 to US$ 5–8 billion by 2020. Almost twothirds of these resources will be needed for Sub-Saharan Africa. The largest needs are for cash transfers, community care workers, early childhood development, block grants for education, M&E monitoring and evaluation, and direct material support. Discussion: The results show that we can significantly improve the coverage of services for vulnerable children with only modest increases in resources. This results from stable or declining numbers of orphans and children living with HIV plus economic growth that is moving more households out of poverty. The results also reflect an important shift toward providing support to strengthen families and communities that care for children rather than direct material support. Conclusion: More resources are required to support children affected by AIDS, but new approaches to provide that support will
be cost effective and have broad social and economic benefits.