Health Care Consolidation: Published Estimates of the Extent and Effects of Physician Consolidation

What GAO Found

Physicians have become increasingly consolidated as the share of physicians in practices owned by other entities has increased over time. For example, studies show that at least 47 percent of physicians were employed by or affiliated with hospital systems in 2024, up from less than 30 percent in 2012. Estimates of the share of physicians consolidated with health insurers and corporate entities vary. Private equity ownership of or investment in physician practices represents a small but growing share of physicians nationally—about 6.5 percent in 2024—but shares varied by specialty and geographic market, according to studies GAO reviewed.

Entities that May Consolidate with Physician Practices

Studies indicate that physician consolidation with hospital systems can lead to increased spending and prices. For example, several studies found increased Medicare spending due to services being provided in more expensive hospital-based settings and increases to prices paid by commercial insurers following hospital-physician consolidation. In contrast, this type of consolidation generally resulted in no changes in the quality of care.

Studies examining the effects of physician consolidation involving private equity firms were limited, but provided some evidence of price increases for commercial insurance.

There were several areas where GAO did not identify rigorous studies on the effects of physician consolidation. These areas include the effects of

• consolidation by hospital systems on patient access to care;
• consolidation by insurers or other corporate entities on spending, prices, quality, or access; and
• private equity investment on quality and access.

Why GAO Did This Study

In recent years, the health care sector in the United States has become increasingly consolidated. This has given rise to concerns that consolidation may result in decreased competition and increased costs to patients, employers, health insurers, and federal health care programs. Physician consolidation occurs when practices merge together or are acquired by or affiliate with other entities.

House Report 117-403 includes a provision for GAO to study the extent health care consolidation is taking place across Medicare and Medicaid markets, and how private equity could be contributing. This report describes what available research indicates about (1) the extent of physician consolidation, including practice ownership by hospital systems, corporate entities, or private equity firms; and (2) the effects of these types of physician consolidation on health care spending and prices, quality of care, and access.

GAO reviewed relevant literature, including peer-reviewed studies and reports published from January 2021 through July 2025 by researchers, stakeholder groups, and others. GAO also interviewed or received written responses from 14 selected stakeholders, as well as four organizations that collect or analyze relevant data on physician employment. Stakeholders included groups representing physicians, hospitals, health insurers, private equity firms, retail companies, and employers.

For more information, contact Leslie V. Gordon at GordonLV@gao.gov.