This paper compares the interoperability approaches of three countries: Taiwan, Denmark and Canada. The work maps out how various countries have addressed the interoperability problems as well as what factors affect decisions and the result, and in what manner. The key findings are as follows: (1) The federal government's ability to mandate standards affects choice of interoperability strategy; (2) E-Health status influences choice of interoperability strategy; (3) Differences in geography, population, and demographics affect the selection of national strategies towards interoperability.