Medicaid ACOs Show a Path Toward Maternal Health Equity in the United States

Medicaid pays for more births in the United States than any other insurer, covering roughly four in ten deliveries nationwide, and that scale gives the program an influence over maternal health that few other levers can match. Against a backdrop in which American maternal mortality rates far exceed those of other wealthy nations and fall disproportionately hard on Black and Hispanic communities, researchers have been asking whether the program’s newer delivery models can translate financial incentives into better, fairer care. A new study led by scientists at Boston University School of Public Health, published in The Milbank Quarterly, offers one of the most detailed answers to date. It finds that Medicaid Accountable Care Organizations in Massachusetts—provider networks rewarded for improving outcomes rather than simply delivering services—did measurably improve the quality of maternal care when contract requirements, resources, and infrastructure were deliberately aligned with maternal health goals.

The study draws on interviews with leaders, clinicians, and care coordinators from six of the seventeen Medicaid ACOs operating in Massachusetts between 2018 and 2024. MassHealth, the state’s Medicaid program, launched its first ACOs under a section 1115 waiver in 2018 and renewed and expanded the program under a second five-year waiver in 2023. This makes the Massachusetts experience the first qualitative assessment of how Medicaid ACO programs implemented maternal health initiatives across multiple waiver periods. It also builds on earlier quantitative work by several of the same researchers, which linked ACO participation to improvements in maternity care engagement and quality—though not yet in hard health outcomes—with effects that varied across different ACO models.

The central finding is deceptively simple: metrics matter. During the first waiver period, ACO contracts required only a single maternal health metric—timely prenatal care. The second waiver period dramatically expanded the requirements, adding a metric for timely postpartum visits and mandating postpartum depression screening. Those contractual obligations, the researchers found, prompted organizations to adapt existing programs or build entirely new ones. Study lead and corresponding author Dr. Shannon Ogden, now a postdoctoral research fellow at the Kaiser Permanente Division of Research who conducted the work as a graduate research assistant at Boston University, explained that instituting maternal health-related metrics at the organizational level does push ACOs and healthcare organizations to develop the programs needed to meet those metrics and to track patients’ engagement. Leaders she interviewed, however, also acknowledged remaining gaps, signaling that considerable work lies ahead even in a state often viewed as a policy leader.

The mechanics of that change are instructive for policymakers elsewhere. With the support of care coordination teams, ACO leaders and clinicians reported that they were able to engage pregnant patients in prenatal care sooner, track births as they occurred, and motivate attendance at postpartum visits once the metrics were introduced. The Massachusetts policy environment reinforced these efforts: alongside the expanded contract requirements, the Commonwealth extended Medicaid coverage from sixty days to twelve months after delivery and began covering doula services, a combination that widened the window during which vulnerable patients could receive supported care.

Yet the study is equally candid about the formidable challenges that surfaced, and it finds that these varied substantially depending on the type of ACO model. Primary care-led ACOs, which are not embedded within comprehensive health systems, especially struggled to track patients’ care delivered out of network and over time. System delays in identifying pregnancies complicated efforts to reach people early in gestation, when interventions matter most. The researchers argue that these implementation barriers—rather than any inherent flaw in the ACO concept—explain much of the unevenness in results, and they offer recommendations that Massachusetts and other states can use to overcome the obstacles in maternal healthcare delivery.

Some of the most vivid findings concern the ingenuity of frontline care coordinators. Senior author Dr. Lois McCloskey, clinical professor of community health sciences at Boston University School of Public Health, described how coordinators worked around the siloed nature of medical care, doggedly following new mothers after birth to ensure they attended their postpartum visits. Many ACOs met the second waiver’s requirements by tailoring programs originally designed for patients with complex chronic illness to the needs of mothers experiencing pregnancy and postpartum complications. But McCloskey also flagged a structural blind spot: contracts did not require the same intensity of follow-up beyond the immediate postpartum period of roughly six to ten weeks after birth. That gap is clinically consequential. It is precisely in the extended postpartum period, she noted, when mothers—especially those with complications—are juggling the most and are most likely to fall through the cracks, and it is when they are most at risk for severe morbidity. In fact, about one-third of maternal deaths occur in this extended postpartum window, and many of them are preventable.

Doula care emerged as another priority of the second waiver period, and the evidence base behind it is compelling: continuous support from a trained doula has been shown to build trust between patients and the healthcare system and to improve equity in maternal care, benefits that are especially relevant for the Black and Hispanic patients who bear the brunt of maternal mortality disparities. ACOs that had already established a doula program or an effective care coordination team were able to deliver this service, but others reported difficulty hiring enough doulas within MassHealth’s network to meet demand. The workforce bottleneck illustrates a recurring theme in the study: mandates can create the will to act, but supply-side capacity determines whether that will becomes care.

The ACOs also broadened their focus during the second waiver period to address patients’ social needs—stable housing, adequate food, reliable transportation, and affordable utilities—which the Centers for Medicare and Medicaid Services and a growing body of research identify as significant drivers of maternal health. Pregnant and postpartum patients were screened for eligibility to participate in FLEX Services, MassHealth’s program allowing ACOs and other healthcare organizations to partner with community organizations to meet these needs. Care coordinators reported barriers here as well, including a lack of provider awareness of the program and burdensome application processes, though the researchers note that Massachusetts’ subsequent expansion of the FLEX program after the study period ended may have eased some of these problems. As Dr. Ogden observed, this holistic orientation inherently supports maternal health: helping patients find housing, pay for food, secure a job, or keep the electricity on can reduce the risk of poor outcomes before, during, and after pregnancy.

The study’s recommendations follow directly from its evidence. The research team urges states and healthcare systems to expand maternal healthcare performance metrics and patient tracking beyond the immediate postpartum period, and to invest in the innovations needed to strengthen care coordination and integration for pregnant and postpartum people. Sustainable change, as McCloskey emphasized, requires more than metrics; it requires sufficient, tangible resources to make change meaningful. The work was coauthored by researchers at W2 Consulting Corporation, Harvard Medical School and the Harvard Pilgrim Health Care Institute, and Boston University Chobanian and Avedisian School of Medicine, and forms part of a larger research program led by Dr. Megan Cole of Harvard Medical School, funded by a $3.8 million grant from the National Institute on Minority Health and Health Disparities. If states heed the lessons from Massachusetts, the researchers argue, strategic direction and investment of this kind could contribute meaningfully to reversing the alarming maternal morbidity and mortality rates that persist in the United States—and that continue to burden Black and brown communities most of all.

Subject of Research: How Medicaid Accountable Care Organizations implement maternal health initiatives to improve care quality and equity

Article Title: How Medicaid ACOs can lead the US towards maternal health equity

Article References: How Medicaid ACOs can lead the US towards maternal health equity. (n.d.). Original publication

Image Credits: AI Generated

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Keywords: Medicaid ACOs, maternal health equity, MassHealth, postpartum care, prenatal care, postpartum depression screening, doula services, care coordination, social needs, The Milbank Quarterly, maternal mortality, health policy