The American Osteopathic Association (AOA) agreed to combine its graduate medical education programs with the Accreditation Council for Graduate Medical Education (ACGME) between July 1, 2015 and June 30, 2020 in an initiative called the Single Accreditation System (SAS). The objective of our study was to identify the impact the SAS had on the ACGME, family medicine (FM), and implications for the future of FM. We collected and compiled data from the AOA, ACGME, and the National Residency Matching Program (NRMP). Analysis reveals the effects that the addition of former 122 AOA-accredited FM residencies had on the ACGME and FM programs. Several osteopathic FM programs encountered challenges meeting ACGME accreditation standards. As of June 1, 2020, 89 of 122 accreditation applications received initial or continuing accreditation; the others had accreditation issues to resolve. The Osteopathic Recognition program emphasizing training in osteopathic principles and practices was a popular option in FM residencies. Fewer DOs serve as program directors in former AOA-accredited FM residencies. The SAS has shifted the balance in the percentages of MDs, DOs, and international medical graduates (IMGs) in FM. Trends in FM show that as more DOs enter the NRMP the percent of MDs and IMGs decreases. In the future, it is projected that DOs will outnumber MDs and IMGs in ACGME FM residencies. The 51 new medical schools started between 2010 and 2020 will generate a test for the integration of their graduates into GME. Increased competition for FM residencies is expected.