Developing countries are now following the steps of developed countries in implementing universal health coverage. Healthcare systems and policies differ across countries resulting in various levels of medicine access. To evaluate which systems and policies lead to better access, we need a measure to compare how well countries provide access to medicine for their populations. Using IMS proprietary data as well as public sources, our analysis proposes a Country Access to Medicines Index that compares and ranks countries on access to medicine outcomes across four pillars: medicine reimbursement coverage, time to reimbursement, medicine affordability and support for innovation. Medicine reimbursement coverage measures private or public insurance cover for a representative basket of medicines across major communicable and non-communicable diseases. It has three components: share of population covered, share of medicines covered and share of costs covered. The time to reimbursement pillar measures average time to reimbursement for the selected basket. The affordability pillar measures relative cost of medicine basket compared to the international average both in absolute terms and as a share of per capita GNI in each country. The innovation pillar measures local patents and investment in R&D. We used this index to compare and rank more than 30 developed and developing countries. We then look at the policies in these countries to identify features that lead to better index scores. We find that five broad factors can help explain access to medicines performance. First is the level of health financing. Second is a structured and transparent pricing and patient access system that prioritises resource allocation to high need diseases and sets economically justifiable or value based prices. Third is the development of healthcare infrastructure. Fourth is the provider and pharmacy incentives that promote appropriate use of medicine. And finally, a system that protects intellectual property rights.