The Ministry of Health and Welfare in Taiwan has indicated that a new financing mechanism broadening the premium base from the payroll tax to family income will be proposed under third-generation National Health Insurance. This study compared the existing system with the new financing mechanism, analyzed the advantages and shortcomings based on considerations of equity, neutrality and administration, and reviewed the related controversies caused by enlarging the premium base. We also provide suggestions for the government in formulating third-generation National Health Insurance in the future.