Research ObjectiveUnmet social needs including poverty, housing, or food instability run deeper in the United States compared with ten other high‐income countries, as identified by previous Commonwealth Fund International Patient Surveys. US primary care physicians (PCPs) are increasingly tasked with screening for these needs, given their centrality in providing coordinated and patient‐centered care. This study compares social needs screening rates among US PCPs with those in other high‐income countries, and explores factors associated with screening.Study DesignCross‐sectional analysis of data from the 2019 Commonwealth Fund Survey of Primary Care Physicians, which included a random sample of PCPs contacted between January and June 2019. Screening for social needs was defined as the share of PCPs that reported that they or other personnel in their practice usually screen patients for unmet needs relating to housing, financial insecurity, food insecurity, transportation, utilities, domestic violence, or social isolation/loneliness. We explored the likelihood of screening for any of these needs using logistic regressions adjusted for practice characteristics and demographic variables.Population Studied13 184 PCPs in Australia, Canada, France, Germany, the Netherlands, New Zealand, Norway, Sweden, Switzerland, the United Kingdom, and the United States (500‐2569 per country).Principal FindingsUS PCPs were significantly more likely to report screening for social needs (29%) than in most other countries (9‐25%) except France (29%), as well as most individual needs including financial security (19% vs 4‐14% in all other countries), transportation needs (14% vs 2‐12% all other), and social isolation/loneliness (15% vs <1‐7% all other). US physicians remained significantly more likely than those in other countries to screen for social needs, even after adjusting for practice and demographic characteristics (ORs: 0.23‐0.71, Ps < .001 vs other countries except France). PCPs in practices with a social worker were more likely to screen than those without (31% vs. 19%; OR 1.80, P < .001). Among US PCPs, those in practices employing community health workers (45% vs 26%; OR 2.11, P < .001), that saw predominantly (≥50%) Medicaid patients (39% vs 28%; OR 1.53, P = .002), and federally qualified health centers (43% vs 27%; OR 1.97, P < .001) were significantly more likely to screen. Across countries, PCPs who screened were slightly more likely to report job‐related stress (52%) than those who did not (48%; OR 1.12, P = .010, adjusted); however, this was lower for PCPs that had a social worker at their practice (42% vs 55%; OR 0.58, P < .001).ConclusionsUS PCPs more often screen for social needs than those in most other high‐income countries. US practices that employ social workers or community health workers, as well as safety‐net settings, more often screened for social needs. PCP screening for social needs is associated with higher job‐related stress levels, which was attenuated by having a social worker at the practice.Implications for Policy or PracticeUS primary care physicians, particularly those in safety‐net settings, may be more often tasked with screening for patient social needs than their counterparts abroad, in part because of a lack of a robust social safety‐net system. To avoid social screening potentially contributing to physician stress, health systems and payers may want to consider team‐based approaches to screening.Primary Funding SourceThis study was supported by the Commonwealth Fund.