BackgroundResearch shows general increases in child maltreatment reports in the U.S. However, less is understood about how reporting varies across states and changes over time, from a perspective of referral sources. While recent studies during COVID-19 reported a reduction in maltreatment referrals, predominantly school referrals, little research has examined changes in maltreatment referrals by referral sources before the pandemic and how different referral sources are associated with case outcomes, particularly out-of-home placement. ObjectivesThis study examined 1) variations across states and changes over time in maltreatment reporting by referral source and 2) the relationship between referral sources type and two case outcomes: substantiated maltreatment and out-of-home placement. Participants and settingWe used 2008–2018 data (N = 24,349,293) from the National Child Abuse and Neglect Data System. MethodsWe used descriptive trend analysis and pooled, fixed effects binary logistic regression. ResultsWe found gradual increases in reporting during 2008–2018, with substantial variations across states and referral sources. States rely differently on certain reporter types, while we see the largest increase in education referrals and a small decrease in social services referrals. Regression results showed that education referrals were less likely to result in out-of-home placement; law enforcement referrals were most likely to be substantiated, while social service referrals were most likely to result in out-of-home placement. ConclusionThis study makes unique contributions to literature by expanding our knowledge of referral sources and examining the likelihood of substantiation and out-of-home placement by referral source type. We provide child welfare policy and practice implications.