Hospital-employed physicians provide primary care within the hospital or within community-based office practices. Yet, little is understood regarding the influence of hospital location and ownership on the delivery of low-value care.To assess the association of hospital location and hospital ownership with the provision of low-value health services.This study compared low-value service use after primary care visits at hospital-based outpatient practices from January 1, 1997, to December 31, 2011, vs community-based office practices and at hospital-owned vs physician-owned community-based office practices from January 1, 1997, to December 31, 2013. Logistic regression models adjusted for patient and health care professional characteristics and year, and weighted results were used to reflect population estimates. Results were also stratified by symptom acuity and whether a generalist physician (eg, general internist or family practitioner) was the patient's primary care provider. This study used nationally representative data from the National Ambulatory Medical Care Survey (January 1, 1997, to December 31, 2013) and the National Hospital Ambulatory Medical Care Survey (January 1, 1997, to December 31, 2011) on outpatient visits to generalist physicians. Participants were patients seen with 3 common primary care conditions, namely, upper respiratory tract infection, back pain, and headache.The use of antibiotics (for upper respiratory tract infection), computed tomography or magnetic resonance imaging (for back pain and headache), radiographs (for upper respiratory tract infection and back pain), and specialty referrals (for all 3 conditions).This study identified 31 162 visits for upper respiratory tract infection, back pain, and headache, representing an estimated 739 million US primary care visits from 1997 to 2013. Compared with visits with community-based physicians, patients in visits to hospital-based physicians were younger (mean age, 44.5 vs 49.1 years; P < .001) and less frequently saw their primary care provider (52.7% vs 81.9%, P < .001). Although antibiotic use was similar in both settings, hospital-based visits had more orders for computed tomography and magnetic resonance imaging (8.3% vs 6.3%, P = .01), radiographs (12.8% vs 9.9%, P < .001), and specialty referrals (19.0% vs 7.6%, P < .001) than community-based visits. Multivariable adjustment and symptom acuity stratification revealed similar findings. Visits with a generalist other than the patient's primary care provider were associated with greater provision of low-value care but mainly within hospital-based settings. Practice patterns were similar among hospital-owned vs physician-owned community-based practices with the exception of specialty referrals, which were more frequent in hospital-owned community-based practices.Visits to US hospital-based practices are associated with greater use of low-value computed tomography and magnetic resonance imaging, radiographs, and specialty referrals than visits to community-based practices, and visits to hospital-owned community-based practices had more specialty referrals than visits to physician-owned community-based practices. These findings raise concerns about the provision of low-value care at hospital-associated primary care practices.