The World Health Organization (WHO) resolution calling on Member States to work towards achieving universal health coverage (UHC) has increased the need for prioritizing health spending. Such need will soon accelerate as low- and middle-income countries transition from external aid. Countries will have to make difficult decisions on how best to integrate and finance previously donor-funded technologies and health services into their UHC packages in ways that are equitable, and operationally and financially sustainable. The International Decision Support Initiative (iDSI) is a global network of health, policy and economic expertise which supports countries in making better decisions about how best and how much to spend public money on healthcare. iDSI core partners include Center For Global Development, China National Health Development Research Center, Clinton Health Access Initiative, Health Intervention and Technology Assessment Program, Thailand / National Health Foundation, Imperial College London, Kenya Medical Research Institute, and the Norwegian Institute of Public Health. In May 2019, iDSI convened a roundtable entitled Why strengthening health systems to make better decisions is a Best Buy. The event brought together members of iDSI, development partners and other organizations working in the areas of evidence-informed priority-setting, resource allocation and purchasing. The roundtable participants identified key challenges and activities that could be undertaken by the broader health technology assessment (HTA) community to further country-led capacity building, as well to foster deeper collaboration between the community itself. HTA is a tool which can assist governments and development partners with evaluating alternative investment options in a defensible and accountable fashion. The definition and scope of HTA, and what it can achieve and support, can be presented more clearly and cohesively to stakeholders. Organizations engaging in HTA must develop deeper collaboration, and integrate existing collaborations, to ensure progress in developing HTA institutionalization globally is well organized and sustainable.