ImportanceDiversity is an essential element of an effective health care system. A key to developing a diverse workforce is establishing a diverse student population in health professions programs.ObjectiveTo examine the diversity of students in Doctor of Medicine (MD), Doctor of Osteopathic Medicine (DO), Doctor of Dental Surgery (DDS), Doctor of Dental Medicine (DMD), and Doctor of Pharmacy (PharmD) programs with emphasis on the trends of underrepresented minoritized groups (American Indian or Alaska Native, Black or African American, Hispanic or Latino, and Native Hawaiian or Other Pacific Islander) and sex relative to the overall age-adjusted US population.Design, Setting, and ParticipantsThis cross-sectional study used deidentified, self-reported data from 2003 to 2019 from the Association of American Medical Colleges, American Association of Colleges of Osteopathic Medicine, American Dental Education Association, American Dental Association, and American Association of Colleges of Pharmacy. Data analysis was performed from 2003 to 2004 and from 2018 to 2019.ExposuresData on the race, ethnicity, and sex of applicants, matriculants, and degrees conferred by health professions programs were collected and compared with the age-adjusted population in the US Census (aged 20-34 years) over time.Main Outcomes and MeasuresThe main outcomes were trends in the proportions of underrepresented minoritized groups and sex diversity among applicants, matriculants, and degrees conferred relative to the overall age-adjusted US population. Trends were measured using the representation quotient, which is defined as the ratio of the proportion of each subgroup to the total population of applicants, matriculants, or graduates relative to the proportion for that subgroup within the US Census population of similar age. Regression analysis was used to evaluate the trend over time.ResultsA total of 594 352 applicants were analyzed across the examined programs. From 2003 to 2019, the proportions of individuals from underrepresented groups increased for DDS and DMD (applicants, from 1003 of 8176 to 1962 of 11 298 [5.1%]; matriculants, from 510 of 4528 to 966 of 6163 [4.2%]; degrees awarded, from 484 of 4350 to 878 of 6340 [2.7%]), PharmD (applicants, from 9045 of 71 966 to 11 653 of 50 482 [9.0%]; matriculants, from 5979 of 42 627 to 10 129 to 62 504 [6.3%]; degrees awarded, from 922 of 7770 to 2190 of 14 800 [3.0%]), and DO (applicants, from 740 of 6814 to 3478 of 21 090 [5.4%]; degrees awarded, 199 of 2713 to 582 of 6703 [1.4%]) programs, but decreased for MD programs (applicants, from 6066 of 34 791 to 7889 of 52 777 [−2.3%]; matriculants, 2506 of 16 541 to 2952 of 21 622 [−2.4%]; degrees awarded, from 2167 of 15 829 to 2349 of 19 937 [−0.1%]). Compared with age-adjusted US Census data, all programs had more Asian students and fewer male, American Indian or Alaska Native, Black or African American, Hispanic or Latino, and Native Hawaiian or Other Pacific Islander students (representation quotient <1).Conclusions and RelevanceIn this cross-sectional study, most of the health professions in the study saw increases in underrepresented minority applicants, matriculants, and degrees conferred from 2003 to 2019; however, all programs were below the age-adjusted US Census data. The increased racial, ethnic, and sex diversity in the programs illustrates progress, but additional strategies are needed to achieve a more representative health care workforce.