OBJECTIVE:To compare publicly available information on aged care systems in 7 countries to determine the degree of transferability for research on aged care between these countries. DESIGN:A cross-country comparative analysis. SETTING:Aged care systems in 7 countries classified as liberal welfare states (Australia, Canada, Japan, New Zealand, Switzerland, United Kingdom, and United States). MEASURES:This study involved the search and review of international data sets, government reports and national statistics, and relevant peer-reviewed literature. Information was extracted for 24 variables at the macro (societal), meso (organizational), and micro (individual) levels to enable a multilevel comparison of aged care systems in each country. RESULTS:The structured search identified 63 relevant documents. All 7 countries included in the review were overall generally comparable across the 3 domains with some expected variations. Comparison of information was not possible for all variables owing to a paucity of publicly available information reported in a consistent manner. Using Australia as a reference point, Canada and New Zealand were the most comparable with Australia, followed by the United Kingdom, United States, and Switzerland. Japan was the least comparable country with Australia based on the variables considered. CONCLUSIONS AND IMPLICATIONS:This is the most recent collation and detailed comparison of national-level information on aged care systems in countries classified as liberal welfare states. This information provides policy makers in these countries the data necessary to determine the degree contemporary research findings from another country are transferable to their local aged care system. Efforts to improve the health, well-being, and quality of care for older people continue to be hampered by the overall paucity of consistently reported standardized data to enable valid international comparisons. Optimal use of standardized data also requires developing explicit criteria to describe the key factors to be considered in determining transferability of an intervention from 1 country to another.