This textbook for graduate and postgraduate university students and for healthcare policymakers reviews a set of countries in the Organisation for Economic Co-operation and Development (OECD) that have introduced universal access to healthcare through an incremental expansion of health insurance coverage over time. This second volume is a companion to Volume 1, A Comparative Review of Landmark Health Reforms in the OECD, which reviews a different set of countries that approach universal access to healthcare via a 'Big Bang' reform process instead.The first two chapters of this volume provide a framework for financing universal access to healthcare through expansion of health insurance, rather than a government-financed National Health Service. The subsequent chapters present case studies of a) the USA which is still struggling; and b) 11 other OECD countries that succeeded in introducing reforms to finance universal access to healthcare for their population in the 20th century, through incremental health insurance reforms.The book's detailed review of the current situation in the USA shows how the road to universal access to healthcare has been a long and tortuous process, spanning more than 100 years of on-and-off reforms. The recent expansion of health insurance coverage in the USA under the Affordable Health Care Act, and current threats to reverse the benefits of this reform, have once again focused the world's attention on just how difficult it is to expand coverage at an affordable cost. Despite being the one of the richest countries in the world in terms of per capita income, and spending more on healthcare than anywhere else in the world, the USA remains among the few OECD countries — including Turkey and Mexico — that still has not achieved the elusive goal of providing access to affordable healthcare to its whole population.The subsequent 11 case studies show how reforms leading to universal access to healthcare were not a one-size-fits-all process and did not imply coverage for all people for everything. Rather, universal access to healthcare was a delicate balance between three critical dimensions: who is covered, what services are covered and how much of the cost is covered through some form of prepayment. The OECD experience has been that there are important trade-offs between these three dimensions. No country in the world is rich enough to bear the costs of providing unrestrained access to a limitless range of services for their whole population. Rather, compromises were made that reflect the social contract and political realities of the time of expansion in coverage in the respective countries.The concluding two chapters focus on the lessons learned from the OECD and recommendations for policymakers and others both in the USA and elsewhere who are planning similar reforms.