The coverage rate for the Complete Basic Immunization (IDL) in Dairi Regency has shown a downward trend, falling from 76.17% in 2024 to 60.2% in 2025. This achievement has not met the 77% target set in the Dairi Regency Health Office’s Strategic Plan. This situation calls for appropriate policy strategies to expand immunization coverage and strengthen disease prevention among infants. This study aims to identify priority policy alternatives to increase RCI coverage in Dairi Regency. The study employed policy analysis through the review and organization of secondary data and supporting documents, including relevant regulations and health references. A number of policy alternatives were then evaluated using six assessment dimensions: effectiveness, efficiency, adequacy, equity, responsiveness, and feasibility. The prioritization of alternatives was based on the assessment results of key personnel within the Dairi Regency Health Office. The evaluation identified three policy intervention options: optimizing the management of Adverse Events Following Immunization (AEFI) alongside pre-vaccination counseling; strengthening the role of community health workers and community leaders in providing education; and expanding public communication regarding the benefits of immunization. Based on the weighted results, the first option ranked highest with a score of 27, followed by the involvement of community health workers and community leaders with a score of 25, while public education received a score of 20. Strengthening the management of adverse events following immunization (AEFI) integrated with pre-immunization counseling was identified as the primary policy option to address low IDL coverage in Dairi Regency. Its implementation must be supported by consistent service procedures, readiness of AEFI management facilities, and the integrated delivery of immunization education and monitoring. The implementation of this strategy is expected to strengthen parents’ trust in immunization services and support the prevention of vaccine-preventable diseases.