Abstract Introduction This study examined the extent of provider consolidation across the outpatient sector overall and analyzed variation by ownership type, including vertically integrated health systems and large corporate owners. Methods Using data from the Agency for Healthcare Research and Quality (AHRQ) Compendium of US Health Systems and the IQVIA OneKey Database, we analyzed changes from 2020 to 2023 in the number and share of outpatient sites and outpatient physicians affiliated with health systems and corporate owners, overall and variation by profit status, owner size, and geographic scope. Results The number of outpatient physicians classified as independent or other type decreased by 34 770 (−7.0 percentage points) from 2020 to 2023. Outpatient consolidation into health systems and corporate owners was relatively high in 2020 and increased modestly from 2020 to 2023. Data validation identified some risk of misclassification of parent ownership status with a potential to bias upwards the prevalence of corporate ownership. Conclusion Our findings on changes in outpatient consolidation provide a baseline for tracking the growth in parent ownership across the outpatient sector overall and highlight the critical need for more accurate and standardized data on ownership and organization to address key policy issues related to competition, antitrust, and quality impacts.
Furukawa et al. (2025) studied this question.