Healthcare Insights
Largest obstetrics/gynecology physician group practices
Obstetricians and gynecologists (OB/GYNs) provide essential, lifelong care for women. Their work spans preventive screenings, reproductive health management, prenatal and postpartum care, labor and delivery, surgical procedures, and the diagnosis and treatment of complex gynecologic conditions.
How many obstetrics/gynecology physician group practices are there in the U.S.?
According to our database, we track more than 6,000 physician group practices with a specialty of OB/GYN. Many of these groups are multispecialty organizations, with OB/GYN identified as the primary specialty based on the most common specialties among the physicians associated with the practice.
Below, we used data from our PhysicianGroupView product to look at the top physician group practices with the most physicians with a primary specialty of OB/GYN.
| Rank | Definitive ID | Physician group name | State | # of OB/GYNs | Explore dataset |
|---|---|---|---|---|---|
| 1 | 550748 | Southern California Permanente Medical Group | CA | 894 | Explore |
| 2 | 550751 | The Permanente Medical Group | CA | 881 | Explore |
| 3 | 717580 | Ascension | IL | 702 | Explore |
| 4 | 577713 | NYU Langone Health Physicians (FKA NYC University Physicians Network) | NY | 620 | Explore |
| 5 | 759259 | Kadlec Medical Associates | WA | 547 | Explore |
| 6 | 707763 | Saint Johns Physician Partners (AKA Providence Saint Johns Health Center Physicians) | CA | 537 | Explore |
| 7 | 975490 | Pediatrix Medical Group | FL | 535 | Explore |
| 8 | 703832 | Hackensack Meridian Health Physicians (FKA Hackensack Meridian Health Medical Group) | NJ | 521 | Explore |
| 9 | 1047395 | HCA Florida Healthcare Physicians | FL | 487 | Explore |
| 10 | 550221 | Advocate Medical Group | IL | 480 | Explore |
| 11 | 746511 | CHRISTUS Health Physicians (FKA CHRISTUS Physician Group) | LA | 420 | Explore |
| 12 | 1073940 | Hill Physicians | CA | 408 | Explore |
| 13 | 618527 | Intermountain Health Physicians (FKA Intermountain Healthcare Medical Group) | CO | 399 | Explore |
| 14 | 550835 | University of Pittsburgh Physicians (AKA UPMC Physicians) | PA | 390 | Explore |
| 15 | 550238 | Aurora Health Care Physicians (FKA Aurora Health Care Medical Group Inc) | WI | 384 | Explore |
| 16 | 1073981 | Unified Women’s Healthcare | FL | 383 | Explore |
| 17 | 550558 | Axia Women’s Health (FKA Regional Women’s Health Group) | NJ | 378 | Explore |
| 18 | 1074136 | Health Care LA IPA (AKA HCLA IPA) | CA | 366 | Explore |
| 19 | 678171 | Ob Hospitalist Group (AKA OBHG) | SC | 358 | Explore |
| 20 | 597090 | RWJBarnabas Health Medical Group (FKA Barnabas Health Medical Group) | NJ | 358 | Explore |
Fig. 1 Analysis of data from the Definitive Healthcare PhysicianGroupView product. The number of practices represents only those listed as “active” in our database. Data accessed February 2026.
What is the largest obstetrics/gynecology physician group in the U.S.?
According to our data, the physician group practice with the largest number of obstetricians-gynecologists in the U.S. is Southern California Permanente Medical Group with 894 physicians with a primary specialty of OB/GYN. It is closely followed by The Permanente Medical Group, which reports 881 OB/GYN physicians and Ascension with 702 OB/GYN physicians.
Geographically, California is particularly prominent, with multiple groups in the top 20. Florida, New Jersey, and Illinois also show strong representation.
Why target obstetrics/gynecology physician groups?
Vendors across the healthcare landscape can find value in targeting OB/GYN physician group practices.
First, OB/GYNs often serve as a critical primary care touchpoint for many women throughout their lives. They also provide preventive services, reproductive and fertility care, perform surgeries, manage pregnancies, and much more. This breadth often makes these professionals influential decision-makers across a range of clinical areas, including diagnostics, imaging, pharmaceuticals, medical equipment, digital health tools, and patient engagement platforms. Simply engaging with an OB/GYN physician group can potentially open access to multiple service lines and a large patient population and form long-term relationships.
Second, many groups have tight partnerships with integrated delivery networks (IDNs) or may even be embedded within one. This concentration means vendors can reach a large number of clinicians and sites through centralized contracting and standardized technology stacks, improving sales efficiency compared to targeting fragmented solo practices.
Third, OB/GYN practices are usually deeply connected to hospital systems and referral networks. Labor and delivery services drive inpatient volume; surgical procedures contribute to OR utilization, and maternal-fetal referrals influence downstream specialty care. In some markets, OB/GYN groups act as both community anchors and hospital revenue drivers.
Finally, women’s health is an area of considerable demand and policy focus. Birth outcomes, maternal health equity, reproductive services, and access to care remain national priorities. At the same time, rising costs, workforce pressures, regulations, and other challenges are driving OB/GYN groups to invest in innovative technologies, adopt new staffing models, and standardize processes. Vendors that can provide solutions that can improve care quality, make daily operations more efficient, or make it easier and faster for providers to expand into new markets will position themselves for success in the future.
Learn more
Access more market-level intelligence on OB/GYNs and other physicians, nurses, and allied health professionals and the places they work at by getting started with PhysicianGroupView.
Healthcare Insights are developed with data from the Definitive Healthcare product portfolio and federal sources. Want even more insights? Start a free trial now and get access to the latest intelligence on hospitals, physicians, and other healthcare providers.
