Primary care doctors may be consolidating faster than subspecialists

The proportion of physicians in groups of 9 or fewer dropped from 40.1% in 2013 to 35.3% in 2015, while the proportion of those in groups of 100 or more increased from 29.6% to 35.1% during the same time period, the study found.


Primary care physicians have consolidated from smaller to larger group practices at a much faster rate than subspecialists, a study found.

Researchers evaluated data from the CMS Physician Compare public use data sets from June 2013 to December 2015. Results of the study appeared in the September Health Affairs.

The proportion of physicians in groups of 9 or fewer dropped from 40.1% in 2013 to 35.3% in 2015, while the proportion of those in groups of 100 or more increased from 29.6% to 35.1% during the same time period, the study found.

Also, in mid-2013, there were 154,726 unique group practice identifying numbers, with a mean group size of 3.8 (SD, 29.0). The median physician group size was 8.0. By the end of 2015, there were 152,328 unique group practice identifying numbers, with a mean group size of 4.0 (SD, 32.4), and the median physician group size was 10.0.

The greatest changes happened in the smallest and largest group sizes. In June 2013, 22.5% of physicians were in the smallest group size of 1 to 2 physicians, and 17.6% were in practices of 3 to 9 doctors. By December 2015, the proportion of physicians in each group size had dropped to 19.8% and 15.5%, respectively. This was a relative decrease of 12.1% (absolute difference, −2.7 percentage points) and 11.9% (absolute difference, −2.1 percentage points) in the 2 smallest groups, the authors noted. In June 2013, 12.6% of physicians were in the largest group size of 500 or more physicians, and 17.0% were in the next-largest group size of 100 to 499. These proportions grew to 15.4% and 19.7%, respectively, in December 2015. This was a relative increase of 22.5% (absolute difference, 2.8 percentage points) and 15.3% (absolute difference, 2.6 percentage points).

A “stark contrast” in practice sizes occurred between primary care physicians and subspecialists, the authors noted. From June 2013 to December 2015, the percentage of primary care physicians practicing in the smallest group size dropped from 24.8% to 19.1%. The percentage of subspecialists practicing in the smallest group size decreased from 21.0% to 19.9%, relative decreases of 29.8% and 5.6%, respectively. During the same period, the percentage of primary care physicians working in the largest practices increased from 11.4% to 15.9%, while for subspecialists, that category increased from 14.0% to 15.1%, relative increases of 28.3% and 7.7%, respectively.

The authors wrote that several important factors contributed to the trend toward consolidation, including:

  • significant financial and technical challenges involved in running a modern medical practice, such as adopting electronic medical records to comply with meaningful use requirements,
  • broad movement toward population-based contracting arrangements,
  • younger physicians preferring to work in larger group practices, and
  • older physicians in smaller practices retiring.

“Belonging to larger groups should open the pathway for physicians to enter into more risk bearing value-based contracts and, ideally, should increase the quality and value of health care delivery,” the authors wrote. “However, evidence is mixed as to whether physician consolidation will lead to better outcomes and lower costs.”