Background Access to quality essential healthcare services and vaccines for all is key to achieving universal health coverage. Inequities driven by differences in place of residence and socio-economic status persist among different communities hindering the achievement of sustained performance on immunization indicators. Innovative community-based Reach Every Child (REC) interventions at the sub-county and county level can reduce these local inequities. This study determines the effect of an enhanced door-to-door immunization strategy on improving immunization coverage in hard-to-reach areas of Migori. Methods This was a cross-sectional review of District Health Information System 2 immunization data for July and August 2018 for Migori County. During the presidential immunization rapid results initiative (RRI) in July 2018, poorly performing wards/facilities were mapped using the Quantum Geographic Information Systems methodology, and unreached rural-urban populations identified. Through review of facility level Kenya Expanded Programme on Immunization data, 64 health facilities with over 100 unimmunized children each between January 2017 and June 2018 in all sub-counties were prioritized. In August 2018, intensified fixed-point immunization services were offered within the prioritized facilities. Further, a 3-day door-to-door defaulter tracing by community health volunteers and household level immunization by nurses was conducted. Immunization coverage performance for access and utilization for the two periods were compared using z-tests/t-tests. Results Cumulatively, a total of 10,744 and 14,809 children were reached with immunization in July and August respectively for the 64 facilities. There were significant increases in the immunization coverage for BCG (74.4% vs 89.9%, P = 0.0001), Penta 1(96.2% vs 102%, P = 0.0649), Penta 3 (92.3% vs 112.1%, P = 0.0001), MR1 (81.7% vs 111.5%, P < 0.0001) and the fully immunized children at 1 year (78.6% vs 103.9%, P < 0.0001). Penta 3 and MR1 drop-out rates (3.99% vs − 9.86%, P = 0.0007; 15.06% vs − 9.27%, P = 0.0001 respectively) decreased significantly. Similar significant effects were observed at the subcounty levels ( P < 0.05). Conclusion Hard-to-reach populations require multiple REC strategies to reach every child with immunization. Health facilities should actively analyze and use routine immunization data and invest in community health strengthening systems to identify hard-to-reach areas to be targeted with outreaches to improve immunization coverage.