Project Summary
More than three in every ten Medicaid enrollees has a diagnosed mental health condition, and many in this
group face significant barriers accessing the care they need. In most states, Medicaid enrollees with mental
health conditions are covered by managed care organizations, which contract with sets of health care
providers and facilities to deliver medical care to its members. The size, composition, and stability of these
“provider networks” can affect care continuity and treatment outcomes, particularly in mental health, where
provider networks tend to be much smaller than those for physical health. The Centers for Medicare and
Medicaid Services requires each Medicaid managed care provider network to provide sufficient and timely
access to mental health services. However, little evidence exists to help states understand which mental health
network attributes affect patient outcomes and how to design, monitor, and regulate provider networks. Against
these knowledge gaps, the overall objective of this proposal is to estimate the effects of mental health
networks on health care utilization and outcomes for adult Medicaid enrollees with mental health conditions
(including those with serious and mild/moderate mental illness). We propose to use the 2016-2023
Transformed Medicaid Statistical Information System (T-MSIS) Analytic Files (TAF), which provides
comprehensive enrollee-level claims data related to service utilization and prescription use for all states and
the District of Columbia. We hypothesize that network size, provider churn (exit), and provider panel size (a
measure of the degree of plan participation) influence enrollees' mental health care access and outcomes.
Specifically, our aims are to 1) identify mental health network attributes associated with plan switching among
Medicaid enrollees with mental health conditions; 2) determine the effects of changes in network size and
network quality on utilization and patient outcomes; 3) estimate the effects of involuntary network disruption on
patient outcomes; and 4) assess how telemedicine affects the attributes and measurement of mental health
networks. We apply a number of innovations, including the construction of empirical provider networks from
administrative claims data, a focus on psychiatrists and psychiatric mental health nurse practitioners, and a
robust study design to evaluate the impact of mental health provider network attributes on patient-level
outcomes. In collaboration with an advisory committee of Medicaid and mental health policy stakeholders,
results will provide actionable evidence to improve access to high-quality mental health services within a
constrained mental health delivery system.
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