BackgroundPrimary care in the United States is changing: practice size is increasing, there is a growing shortage of primary care practitioners, and there is a heightened prevalence of chronic disease. Given these trends, it is likely that registered nurses will become important members of the primary care team. PurposeThis paper explores the challenges and opportunities in primary care delivery in the 21st century and examines the likelihood of expanded roles for RNs to improve quality and add capacity to the primary care workforce. MethodsWe searched the peer-reviewed and gray literature for publications on primary care, primary care workforce projections, the future of nursing, and team-based care. DiscussionThe number of primary care physicians is expected to decrease in relation to the US population while the number of nurse practitioners is increasing, with the result that more and more patients will see nurse practitioners as their primary care practitioner. However, the primary care practitioner (physicians, nurse practitioners and physician assistants) to population ratio is dropping. As a result, other professionals will be needed to deliver primary care. As the nation’s largest health profession, registered nurses (RNs) are in sufficient supply and have been shown to improve the care of patients with chronic conditions. It is likely that primary care practices of the future will include an enhanced role for RNs, particularly in chronic disease management. ConclusionFor RNs to assume an expanded role in primary care, several barriers need to be overcome: (1) the widespread introduction of payment reform that reimburses RNs to independently provide care for patients, and (2) nursing education reform that includes primary care nursing skills (3) scope of practice clarification for non-advance practice RNs working under standardized procedures.