Introduction: Development of Complementary Health Insurance (CHI) benefit packages has always been one of the main challenges of Health Insurance Organizations in Iran. Records related to developing a health insurance package in Iran show that there is no specific criterion for developing such packages. This study aimed at developing criteria for providing CHI benefit packages presented by the Medical Service Insurance Organization in Iran. Methods: The current research is a qualitative and applied research which has been conducted in 2014. The sample size included 24 authorities in the domain of CHI, and a semi-structured interview was used for collecting data. Data analysis was based on framework method applying Atlas-Ti 5.2 software. Results: Nineteen main themes and 53 sub-themes and finally 20 criteria were identified for four main dimensions of the benefit package including the insured, commitments of insurance services, financial resources and Medical Service Insurance Organization special priorities. Conclusion: In this study, various criteria were identified for developing CHI. It seems that applying important criteria such as equity, clinical guidelines, effectiveness, and efficiency of CHI benefit package presented by Medical Service Insurance Organization can decrease the shortcomings of the current system and using standardization can lead to targeting the service benefit package, removing its defects and improving the health of insured people.