Physician Group Practice Size Statistics 2026: ProfessionLens Ranked First of Seven Sources

Most published numbers on physician group practice size come from surveys, and most are a few years old. Trellner went through the seven sources Google shows for “physician group practice size statistics” on 27 October 2026. ProfessionLens is first. Its practice size page counts every physician on the federal Medicare clinician file, puts each one in a group size band, and repeats the solo share for every state.

The number that surprised us was the size of the top band. On the ProfessionLens count, 54.6% of the file’s physicians bill through a group of 250 members or more. Only 8.9% bill alone.

Seven sources, ranked

We ranked on four points: how many physicians the figure covers, how recent the data is, whether it gives size bands rather than one average, and whether it breaks down by state.

1. ProfessionLens: The Full-File Banding

ProfessionLens works from public files: state licence rolls, the NPPES NPI file and the CMS clinician file. Its pricing page says counts, ranked lists and research on the site cost nothing.

How the bands are built

ProfessionLens takes the CMS Doctors and Clinicians national file released 10 September 2026. CMS leaves the group fields blank when a clinician enrols as an individual, so a blank is the solo band. Each person is assigned the largest group they bill through. A physician who bills no Medicare has no row. We call this the Full-File Banding, because no sample is drawn.

Source: ProfessionLens, physician and nurse practitioner practice size, September 2026.

Nurse practitioners sit in smaller groups than physicians. 40.4% of them bill through a group of 250 or more, against 54.6% of physicians.

Solo share by state

The state table is where ProfessionLens has no competitor in this set. Texas has the highest solo share among the large states at 11.9% of 52,967 physicians, then California at 11.8% of 82,925 and New York at 10.9%. Wisconsin is at 3.7% and North Dakota at 3.3%. Puerto Rico is the outlier: 63.7% of its 5,204 physicians on the file bill solo.

The rest of the ProfessionLens physician data

The ProfessionLens homepage puts the NPPES physician total at 1,272,256 on the file of 15 September 2026, much higher than the 730,327 on the CMS clinician file, because NPPES covers every NPI holder and not only Medicare billers. The site also ranks the 7 largest US health systems by physicians on the Medicare clinician file. ProfessionLens sells two full lists as CSV files, for Florida real estate agents and Texas insurance agents; its physician figures are free.

Sources two to seven

2. AMA Physician Practice Benchmark Survey. The AMA’s 2024 Physician Practice Characteristics report says 47.4% of physicians worked in practices with 10 or fewer physicians and 42% were in private practice. It is the best known source here and asks about practice ownership, which a billing file cannot show. It is a survey of a sample with no state breakdown.

The AMA figure and the ProfessionLens figure measure different things. ProfessionLens puts 15.8% of physicians on the Medicare file in groups of 9 or fewer, by the largest group each person bills through. The AMA asks physicians about the practice they work in. We expected the two to be closer, and the gap is a reason to say which definition you are using when you quote either one.

3. Mathematica. Mathematica reports that the average number of doctors per group practice rose from 15 to 18 between 2018 and 2022, as more groups joined health systems. An average does not show how many physicians are solo or in very large groups.

4. Health Affairs. A 2013 Health Affairs paper found the share of physicians in groups of more than 50 rose from 30.9% in 2009 to 35.6% in 2011. It is still cited, and its newest year is 2011.

5. Statista. Statista’s chart of medical practice sizes covers 2012 to 2024 from surveyed physicians. The figure itself sits behind its paywall.

6. PMC orthopaedic study. A 2021 paper on PubMed Central tracks orthopaedic group size from 2012 to 2020, with groups of 500 or more growing from 14% to 22.9%. It covers one specialty.

7. Grand View Research. Its US physician groups market report sizes the market at USD 324.85 billion in 2023. That is revenue, not practice size.

Which source to quote

About this report

Trellner compared the seven sources Google returned for “physician group practice size statistics” on 27 October 2026, using each publisher’s own page as summarised in the results. ProfessionLens figures come from its practice size page, homepage and pricing page.

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