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Medicaid Expansion: Behavioral Health Treatment Use in Selected States in 2014

GAO-17-529 Published: Jun 22, 2017. Publicly Released: Jul 21, 2017.
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Fast Facts

Behavioral health conditions disproportionately affect low-income people. Some states expanded Medicaid to cover low-income adults, as authorized by the Affordable Care Act, so we examined how many people in this expansion group received behavioral health treatment.

In four states—Iowa, New York, Washington, and West Virginia—we found that in 2014:

Up to 1 in 3 Medicaid expansion enrollees received behavioral health treatment.

Psychotherapy visits and antidepressant medications were most commonly used.

In 3 states, enrollment in Medicaid likely increased access to this treatment (most enrollees in the 4th state already had access to it).


Photograph of a medical professional providing medicine to a patient.

Photograph of a medical professional providing medicine to a patient.

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What GAO Found

In four selected states, from 17 to 25 percent of enrollees who were covered by state expansions of Medicaid—authorized by the Patient Protection and Affordable Care Act (PPACA)—had diagnosed behavioral health conditions (mental health and substance use conditions) in 2014. Mental health conditions were more common than substance use conditions; from 11 to 20 percent of expansion enrollees were diagnosed with a mental health condition, compared with 6 to 8 percent diagnosed with a substance use condition. The most common mental health condition category was mood disorders, such as depression. For substance use, substance-related conditions (e.g., addiction to drugs like opioids) were more prevalent than alcohol-related conditions.

From 20 to 34 percent of expansion enrollees in the four selected states received behavioral health treatment in 2014, which includes outpatient services such as psychotherapy or prescription drugs. Treatment rates exceeded rates of diagnosed conditions, in part, because prescription drugs are not recorded with diagnosis codes. Thus, enrollees who only used behavioral health prescription drugs—and no outpatient services—were not counted in the diagnosis totals.

  • The two most commonly used behavioral health service categories were psychotherapy services (visits with a provider aimed at reducing and managing symptoms) and diagnostic services, such as diagnostic evaluations.
  • Antidepressants were the most commonly used behavioral health prescription drug category; over two-thirds of expansion enrollees who used a behavioral health drug took an antidepressant.

Use of Behavioral Health Treatment among Medicaid Expansion Enrollees in Selected States, 2014

Type of behavioral health treatment

Percentage of expansion enrollees


New York


West Virginia

Any behavioral health treatment (services or drugs)





Behavioral health services





Behavioral health drugs





Both services and drugs





Source: GAO analysis of Medicaid data. | GAO-17-529

Officials in three of the four selected states said that expansion enrollees likely had greater access to behavioral health treatment after enrolling in Medicaid. Officials from Iowa, Washington, and West Virginia reported that, compared to being uninsured, expansion enrollees could more easily access treatment, such as community-based mental health services and behavioral health prescription drugs. Officials in New York said expansion enrollees experienced less of a change, because most of its enrollees were previously eligible for Medicaid.

Why GAO Did This Study

Behavioral health conditions disproportionately affect low-income populations. Treatment can improve individuals' symptoms and help avoid negative outcomes. The expansion of Medicaid to cover low-income adults in some states—authorized by PPACA—may have increased the demand for such treatment. However, little is known about the extent to which Medicaid expansion enrollees experienced behavioral health conditions or utilized treatment during the first year of expansion in 2014.

GAO was asked to provide information about the utilization of behavioral health treatment among Medicaid expansion enrollees during the first year of expansion in 2014. For selected states in 2014, this report describes (1) the population of Medicaid expansion enrollees with behavioral health diagnoses, and (2) the use of behavioral health treatment among Medicaid expansion enrollees.

GAO selected four expansion states—Iowa, New York, Washington, and West Virginia—based on, among other criteria, availability and reliability of Medicaid enrollment and utilization data. GAO analyzed Medicaid data on behavioral health diagnoses and treatment use for expansion enrollees for 2014, the most recent year available. GAO also reviewed documents and interviewed Medicaid officials from all selected states to understand how data were recorded, and how treatment for expansion enrollees compared with what was available prior to expansion. The Department of Health and Human Services provided technical comments on a draft of this report, which GAO incorporated as appropriate.

For more information, contact Carolyn L. Yocom at (202) 512-7114 or

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