Latar Belakang Menurut Organisasi Kesehatan Dunia (WHO), hepatitis B adalah masalah kesehatan global, mempengaruhi 257 juta orang di seluruh dunia. Bersadarkan Riskesdas tahun 2018 angka kematian sebesar 887.000 orang meningggal yang penyebabnya adalah hepatitis B. Berdasarkan hasil Survei Kesehatan Dasar (Riskesdas) 2018 proporsi imunisasi HB0 di Indonesia sebesar 83,1% (Riskesdas, 2018). Berdasarkan hasil cakupan imunisasi HB0 Indonesia yang dilansir Riskesdas tahun 2018, pencapaian target cakupan imunisasi HB0 masih di bawah target UCI kecamatan yang ditetapkan Kementerian Kesehatan RI. Sedikitnya 94,4% jumlah bayi di desa (0-7 hari) yang diimunisasi HB0 (Kemenkes RI, 2015).Tujuan dari penelitian yaitu untuk mengetahui pengaruh cakupan imunitas HB0 di Puskesmas KotaMedan.Metode kuantitatif analitik pendekatan desain penelitian cross sectional study. Seluruh populasi adalah seluruh tenaga kesehatan di Puskesmas Kota Medan yang memberikan pelayanan imun dengan teknik pengambilan sampel menggunakan random sampling yang diminati dengan jumlah 55 responden. Data dalam penelitian adalah primer dan sekunder. Analisis data menggunakan pendekatan bivariat dan multivariat.Hasil penelitian ini menunjukkan bahwa cakupan imunisasi HB0 p = 0,030 berpengaruh terhadap motivasi, cakupan imunisasi HB0 p = 0,001 memiliki pengaruh pemantauan, dan cakupan imunisasi HB0 p berpengaruh terhadap lama masa pelayanan. = 0,041. Nilai prediksi dari probabilitas atau persamaan adalah 0,884 (> 0,05).Kesimpulan Ada pengaruh motivasi, supervisi, lama bekerja, terhadap cakupan imunisasi HB0 di Puskesmas Kota Medantahun 2020.Saran Untuk pengawan dan masa kerja mempengaruhi cakupan imunisasi HB0 dengan nilai 88.4%.Pimpinan didorong untuk meningkatkan dan meningkatkan kualitas pengawasan dan menambah insentif, terutama untuk meningkatkan kinerja juru bahasa dan kemudian mempengaruhi perluasan jangkauan kekebalan. Kata Kunci : Imunisasi HB0, Juru Imunisasi,Lama Bekerja, Motivasi, Supervisi ABSTRACT Background: according to the World Health Organization (WHO) Hepatitis B is a world health problem that affects 257 million people worldwide. Based on Riskesdas in 2018, the death rate showed that 887,000 people died because of hepatitis B. Based on the results of the 2018 Riset Kesehatan Dasar (Riskesdas), the percentage who had received HB0 immunization in Indonesia was 83.1% (Riskesdas, 2018). Based on the results of the HB0 immunization coverage in Indonesia reported by Riskesdas 2018 above, it can be seen that the achievement of the HB0 immunization coverage target is still below the UCI sub-district target set by the Indonesian Ministry of Health, which is at least 94.4% of the total number of babies (0-7 days). villages have received HB0 immunization (Kemenkes RI, 2015).Purpose: to know the factors that influence the coverage of HB0 immunization in Health Centers in Medan.Methods: a quantitative analytic survey using a cross sectional study design was used. The population were all health workers who provide immunization services at the Health Centers in Medan with the sampling technique using purposive random sampling with a total of 55 respondents. The data used included primary data and secondary data. Data analysis used bivariate and multivariate approaches.Results of this study indicated that there was an effect of motivation on HB0 immunization coverage with p =0.030, meaning that there was an effect of supervision on HB0 immunization coverage with p = 0.001, and there was an effect of length of service on HB0 immunization coverage with p = 0.041. Supervision was the most dominant variable affecting HB0 immunization coverage with an Exp (B) 10,000 value (95% CI: 2,580-38,756).Conclusion: there was an influence of motivation, supervision, length of work, on the coverage of HB0 immunization at the Medan City Health Center in 2020.Suggestion It is recommended that the leadership improve and improve the quality of supervision, and add incentives, so that health workers can improve their performance, especially immunization officers, so that later it will have an impact on increasing immunization coverage. Keywords: HB0 Immunization, Immunizers ,Motivation, Length of Working, Supervision