Few studies have examined early parenting among girls receiving child welfare services (CWS) or disentangled the relationship between maltreatment, spending time in foster care, and adolescent childbirth. Using population-based, linked administrative data, this study calculated birth rates among maltreated adolescent girls and assessed differences in birth rates associated with spending time in foster care. Of the 85,766 girls with substantiated allegations of maltreatment during adolescence, nearly 18% subsequently gave birth. Among girls who spent time in foster care, the proportion was higher (19.5%). Significant variations (p < .001) were observed in the rate of childbirth across demographic characteristics and maltreatment experiences. When accounting for all of the covariates, spending time in foster care was associated with a modestly higher rate of a first birth (Hazard Ratio [HR] = 1.10; 95% confidence interval = [1.06, 1.14]). While age at first substantiated allegation of maltreatment and race/ethnicity were significant predictors of adolescent childbirth, specific maltreatment experiences were associated with minimal or no differences in birth rates. The findings of this study suggest that the experience of spending time in care may not be a meaningful predictor of giving birth as a teen among CWS-involved adolescent girls and highlight subgroups of this population who may be more vulnerable to early childbirth.