BACKGROUND: Medical professionals are key components of child maltreatment surveillance. Updated estimates of reporting rates by medical professionals are needed. METHODS: We use the National Child Abuse and Neglect Data System (2000-2019) to estimate rates of child welfare investigations of infants stemming from medical professional reporting to child welfare agencies. We adjust for missing data and join records to population data to compute race/ethnicity-specific rates of infant exposure to child welfare investigations at the state-year level, including sub-analyses related to pregnant/parenting peoples substance use. RESULTS: Between 2010 and 2019, child welfare investigated 2.8 million infants; ∼26% (n=731,705) stemmed from medical professionals reports. Population-adjusted rates of these investigations stemming doubled between 2010 and 2019 (13.1-27.1 per 1000 infants). Rates of investigations stemming from medical professionals reports increased faster than did rates for other mandated reporters, such as teachers and police, whose reporting remained relatively stable. In 2019, child welfare investigated ∼1 in 18 Black (5.4%), 1 in 31 Indigenous (3.2%), and 1 in 41 White infants (2.5%) following medical professionals reports. Relative increases were similar across racial groups, but absolute increases differed, with 1.3% more of White, 1.7% of Indigenous, and 3.1% of Black infants investigated in 2019 than 2010. Investigations related to substance use comprised ∼35% of these investigations; in some states, this was almost 80%. DISCUSSION: Rates of child welfare investigations of infants stemming from medical professional reports have increased dramatically over the past decade with persistent and notable racial inequities in these investigations.