All families experience financial and time costs related to caring for their children’s health. Understanding the economic burden faced by families of children with chronic health conditions (CHC) is crucial for designing effective policies to support families. In this prospective study we used electronic health records to identify children between 3 and 17 years old with autism spectrum disorder (ASD), asthma, or neither (control) from three Kaiser Permanente regions and several community health centers in the OCHIN network. We oversampled children from racial and ethnic minority groups. Parent/guardian respondents completed surveys three times, approximately four months apart. The surveys included the Family Economic Impact Inventory (measuring financial, time, and employment costs of caring for a child’s health), and standardized measures of children’s quality of life, behavioral problems, and symptom severity for children with ASD or asthma. We also assessed parenting stress and parent physical and mental health. All materials were provided in English and Spanish. Of the 1,461 families that enrolled (564 ASD, 468 asthma, 429 control), children were predominantly male (79%), with a mean age of 9.0 years, and racially and ethnically diverse (43% non-Hispanic white; 22% Hispanic; 35% Asian, Black, Native Hawaiian, or another race/ethnicity). The majority of survey respondents were female (86%), had a college degree (62%), and were married/partnered (79%). ASD group respondents were less likely to be employed (73%) than those in the asthma or control groups (both 80%; p = .023). Only 32% of the control group reported a household income ≤ $4,000/month compared with 41% of asthma and 38% of ASD families (p = .006). Utilizing a novel measure assessing family economic burden, we successfully collected survey responses from a large and diverse sample of families. Drawing upon the conceptual framework, survey measures, and self-report data described herein we will conduct future analyses to examine the economic burdens related to CHC and the incremental differences in these burdens between health groups. This information will help policy makers to design more equitable health and social policies that could reduce the burden on families.