This study analyzes data from a new Urban Health and Demographic Surveillance (UHDSS) in five slums in Dhaka (North and South) and Gazipur City Corporations to examine the relationship between migration status and maternal and child health service utilization. Migration status was determined by duration in urban slums (<= 9.99 years, 10-19.99 years, 20+ years, and urban-born). Compared to those born in the city, migrants were characterized by significant disadvantages in every maternal, neonatal, and child health (MNCH) indicator under study, including antenatal care, facility-based delivery, doctor-assisted delivery, child immunization, caesarean-section delivery, and use of modern contraceptives. We found that the level of service coverage among migrants gradually converged-but did not fully converge-to that of the urban-born with increasing duration in the city. We observed a strong positive association between wealth and total MNCH coverage, with a more modest association with higher levels of schooling attainment. Women who were engaged in market employment were less likely to receive adequate coverage, suggesting a tradeoff between livelihood attainment and mother-and-child health. After controlling for these socioeconomic and neighborhood variations in coverage, the duration gradient was diminished but still significant. In line with existing studies of healthcare access, this study highlights the persistent and widespread burden of unequal access to maternal and child health care facing migrants to slum areas, even relative to the overall disadvantages experienced in informal settlements.