Inaccurate Medicaid Managed Care Network Lists May Compromise State Oversight of Access to Maternal Health Care

Report Materials

• Full Report (PDF, 1.7 MB)
• Report Highlights (PDF, 370.7 KB)
• Companion Report (OEI-05-24-00090)

Why OIG Did This Review

The United States is experiencing a maternal health crisis, with worse outcomes than in any other high-income country. Access to maternal health care in Medicaid managed care impacts the Nation's overall maternal health outcomes. Medicaid pays for over 40 percent of births and most pregnant Medicaid enrollees are in managed care plans. Centene, Elevance, and UnitedHealthcare are the three largest parent companies operating in Medicaid managed care. As of 2025, these companies had plans that collectively covered over 29 million enrollees in 38 of the 42 States that have comprehensive Medicaid managed care plans.

States are responsible for ensuring that comprehensive Medicaid managed care enrollees have access to maternal health care. One way States oversee access to care is by checking whether plans have enough maternal health providers in their networks. To do this, many States use lists of in-network providers from the plans. If these network lists are inaccurate, it can make it harder for States to know whether enrollees have access to the care they need. We reviewed the accuracy of network lists for maternal health providers from Centene's, Elevance's, and UnitedHealthcare's Medicaid managed care plans in five States.

What OIG Found

Network lists from Centene, Elevance, and UnitedHealthcare Medicaid managed care plans in five States contained inaccuracies that may compromise State oversight of access to maternal health care.

• About one-quarter of maternal health providers in the network lists that plans sent to States reported to OIG that they were not in-network.
• Plans provided no accurate phone numbers for over one-quarter of providers.
• Almost half of providers from network lists were not included in the plans' online provider directories that enrollees use to find providers, further raising concerns about the accuracy of network lists.

OIG released a companion report that evaluated the accuracy of public-facing online provider directories that Medicaid managed care enrollees can use to find maternal health providers.

What OIG Recommends

1. CMS should work with States to improve the accuracy of the provider data they use to evaluate the adequacy of networks in Medicaid managed care.
2. CMS should take steps to support States in holding Medicaid managed care plans accountable for the accuracy of the network lists used for assessing network adequacy.

CMS concurred with both recommendations.