Good health and well-being are the 3rd Goal in UNDP Global Goals. The World Health Assembly requested the World Health Organization (WHO) to start an expanded program on immunization (EPI) to give universal access to vaccines against a set of diseases. Irrespective of the large number of efforts made by different agencies and government institutions, this program is still not achieving the desired coverage. The primary objective of this research was to identify the most critical administrative barriers to implementing this program in the Punjab Province, Pakistan. A sequential exploratory design was used in our study employing both qualitative and quantitative techniques. Qualitative analysis is applied to identify the most critical administrative barriers of the EPI program. A quantitative analysis was then conducted based on the results obtained from qualitative analysis, and rank orders of barriers were received from the same experts of the health department. The case study method was used to investigate the grounds of observations and concepts. The results indicate that twenty-eight barriers can cause implementation problems for this program. Still, the ten barriers that gained the maximum hits are the most important administrative barriers which include “Shortage of vaccinators, mismanagement of vaccines’ cold chain, biometric android application, ice-lined refrigerators, communication gap, inadequate legislation of EPI program, capacity building issues with EPI staff, Misconceptions about EPI program, lack of awareness of the parents and community, refusal cases and inadequate cooperation of lady health workers” are essential administrative barriers. All in all, these barriers are interlinked with each other, and coordinated efforts of the government and the public are highly recommended to address these barriers.