Accountable Care Organizations (ACO) in the United States of America (USA) and Clinical Commissioning Groups (CCG) in the United Kingdom (UK) are new proposed organizations in health services both tasked with a role which includes improving public health. Although there are very significant differences between the UK and USA health systems there appears to be a similar confusion as to how ACO and CCG will regard and address public or population health. The role of ACO in improving population health and evaluating the health needs of their registered and insured patients remains ill-defined and poorly explored. Likewise, in the current UK National Health Service (NHS) reorganisation, control and commissioning of appropriate local health services are passing from Primary Care Trusts (PCT) to new cross-organizational structures (CCG). CCG groups aim to be, like ACO, physician led. They will also assume a role for public or population health, but this role, like that of the newly-forming ACO, is currently unclear. Lessons learned from the USA and UK experience of new organizations tasked with a role in improving public health may inform mechanisms for physician led organizations in the UK and the USA to assess health needs, monitor population health information and improve population health outcomes.