ImportanceCaring for children diagnosed with cancer may adversely affect the mental health (MH) of parents.ObjectiveTo characterize utilization of MH services among parents of children with vs without cancer using nationwide commercial claims data.Design, Setting, and ParticipantsFor this cross-sectional study, the Merative MarketScan Commercial Claims Database was used to identify continuously insured families of children treated for cancer (aged ≤21 years at diagnosis) during 2010 to 2018, compared with families who matched eligibility criteria but did not have a child with a cancer history. Parents were assessed from 18 months before to 12 months after their child’s cancer diagnosis. Analyses were conducted from February 2022 to September 2023.ExposuresChildren’s cancer diagnosis.Main Outcomes and MeasuresOutcomes included parents’ MH-related visits during the first year following their child’s cancer diagnosis. Logistic regressions compared outcomes between families of children with vs without cancer, adjusting for sociodemographic and clinical factors.ResultsThis study included 4837 families of children with cancer (4210 mothers and 4016 fathers) and 24 185 families of children without cancer (21 444 mothers and 19 591 fathers) with continuous insurance enrollment. Most household leads were aged 35 to 54 years (3700 [76.5%] in families of children with cancer vs 17 812 [73.6%] in families of children without cancer) and resided in urban areas (4252 [87.9%] vs 21 156 [87.5%]). The probabilities of parents having anxiety-related visits (10.6% vs 7.0%), depression-related visits (8.4% vs 6.1%), and any MH-related visits (18.1% vs 13.3%) were higher in families of children with vs without cancer. Adjusted analyses showed absolute increases of 3.2 percentage points (95% CI, 2.3 to 4.0; 45.7% relative increase), 2.2 percentage points (95% CI, 1.4 to 3.0; 36.1% relative increase), and 4.2 percentage points (95% CI, 3.1 to 5.3; 31.3% relative increase) in the probabilities of 1 or both parents having anxiety-related visits, depression-related visits, and any MH-related visits, respectively, among families of children with vs without cancer. Such differences were greater in magnitude among mothers than fathers.Conclusions and RelevanceIn this cohort study of privately insured parents, those caring for children with cancer had a higher likelihood of utilizing MH care than other parents. These findings underline the importance of interventions toward targeted counseling and support to better meet MH care needs among parents and caregivers of children with cancer.