Emergency department (ED) visits that could be managed in primary care settings contribute to inefficiencies and increased health care costs. We examined the relationship between area-level social vulnerability and potentially avoidable ED encounters, controlling for individual factors among insured patients. We conducted a retrospective cohort study using the Institute for Health Equity Research Multi-Payer Claims Database, analyzing ED visits from 26,727,123 patients between January 2022 and December 2022. The 3-digit ZIP code Social Vulnerability Index (SVI), a composite measure of community risk, was the primary predictor. ED visits were classified as either primary care treatable (PCT) or ED care needed using the Minnesota algorithm. We applied generalized estimating equations to assess the relationship between the SVI and PCT ED visits, adjusting for individual age, sex, race/ethnicity, insurance type, and comorbidity. Higher SVI scores were significantly associated with an increased likelihood of PCT ED visits (adjusted odds ratio [aOR], 1.77; 95% CI, 1.71-1.83), independent of individual factors. Among the SVI themes, housing and transportation showed the strongest association (aOR, 2.67; 95% CI, 2.55-2.81). Black (aOR, 1.15; 95% CI, 1.12-1.18) and Hispanic patients (aOR, 1.17; 95% CI, 1.15-1.19), as well as Medicaid recipients (aOR, 1.29; 95% CI, 1.28-1.30), also had greater odds of PCT visits. Area-level social vulnerability, particularly related to housing and transportation, is associated with PCT ED visits. Targeted interventions to enhance primary care access in vulnerable communities may help reduce nonemergent ED utilization and associated costs.