title: Estimating the residency expansion required to avoid projected primary care physician shortages by 2035.
abstract: OBJECTIVE
  The purpose of this study was to calculate the projected primary care physician shortage, determine the amount and composition of residency growth needed, and estimate the impact of retirement age and panel size changes.
  
  
  METHODS
  We used the 2010 National Ambulatory Medical Care Survey to calculate utilization of ambulatory primary care services and the US Census Bureau to project demographic changes. To determine the baseline number of primary care physicians and the number retiring at 66 years, we used the 2014 American Medical Association Masterfile. Using specialty board and American Osteopathic Association figures, we estimated the annual production of primary care residents. To calculate shortages, we subtracted the accumulated primary care physician production from the accumulated number of primary care physicians needed for each year from 2015 to 2035.
  
  
  RESULTS
  More than 44,000 primary care physicians will be needed by 2035. Current primary care production rates will be unable to meet demand, resulting in a shortage in excess of 33,000 primary care physicians. Given current production, an additional 1,700 primary care residency slots will be necessary by 2035. A 10% reduction in the ratio of population per primary care physician would require more than 3,000 additional slots by 2035, whereas changing the expected retirement age from 66 years to 64 years would require more than 2,400 additional slots.
  
  
  CONCLUSIONS
  To eliminate projected shortages in 2035, primary care residency production must increase by 21% compared with current production. Delivery models that shift toward smaller ratios of population to primary care physicians may substantially increase the shortage.
authors.affiliation: Robert Graham Center, Washington, DC.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Petterson
authors.affiliation: Virginia Commonwealth University, Richmond, Virginia winstonrliaw@gmail.com.
authors.forename: Winston R
authors.initials: WR
authors.lastname: Liaw
authors.affiliation: University of Virginia, Charlottesville, Virginia.
authors.forename: Carol
authors.initials: C
authors.lastname: Tran
authors.affiliation: Robert Graham Center, Washington, DC.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Bazemore
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004503:Education, Medical, Graduate / Q000706:statistics & numerical data*; D005194:Family Practice / Q000193:education*; D006291:Health Policy; D006301:Health Services Needs and Demand; D006801:Humans; D007231:Infant, Newborn; D007388:Internal Medicine / Q000193:education*; D007396:Internship and Residency / Q000706:statistics & numerical data*; D008875:Middle Aged; D010372:Pediatrics / Q000193:education*; D058007:Physicians, Primary Care / Q000600:supply & distribution*; D011320:Primary Health Care; D012179:Retirement / Q000706:statistics & numerical data; D014481:United States; D000078329:Workforce; D055815:Young Adult
keywords: graduate medical education; health policy; health services research; internship and residency