Foreign-trained doctors in the United States play an indispensable role in providing health care to undeserved communities and fill health care shortages that impact millions of Americans. One-quarter of all practicing physicians in the U.S., around 247,000 doctors, are foreign-trained and therefore likely to be foreign-born. This report examines foreign-trained doctors and the socio-demographic characteristics of the Primary Care Service Areas (PCSAs) where they serve. Data was obtained from the American Medical Association (AMA), the U.S. Census, the American Community Survey and the U.S. Healthcare Resources and Services Administration (HRSA) using zip codes of practice, medical specialty and location where medical degrees were earned. The report finds that foreign-trained doctors were more likely to work in primary-care positions like family medicine, therefore caring for a large swath of the U.S. population, while US-trained doctors pursued specializations such as dermatology and orthopedics. Furthermore, between 30 to 42.5 percent of all doctors in areas that are low income, less educated and have more ethnic minorities were foreign-trained. The projected shortfall of doctors by 2025 (estimated at 46,100 to 90,400 positions) will increase demand for foreign-trained doctors. However, immigration policies related to residency and visa requirements limit the ability of doctors to immigrate and practice medicine in the U.S. The authors urge policymakers to consider the important role foreign-trained doctors play in providing health care to underprivileged communities and to adjust immigration policy accordingly.