Nationally, more than half of Medicaid beneficiaries are enrolled in a  managed care plan. States contract with MCOs to provide a specific set  of Medicaid-covered services to beneficiaries, and MCOs are expected to  report encounter data to state Medicaid programs that allow the Medicaid  administrators to track the services received by enrolled beneficiaries. These studies first  reported that encounter data were suitable for research purposes in  2012. Beneficiaries’ Service Utilization Varied by State, Population, Service Categories, and Length of Enrollment for Selected States

Based on our analysis of encounter data, the number of professional  services utilized by adult and child beneficiaries per year in the 19  selected states ranged widely, with adult beneficiaries typically receiving  more services. Services used by adult beneficiaries included E/M  services, such as office visits and emergency room and critical care  services; procedural services, such as surgery and ophthalmology;  ancillary services, such as pathology and lab services and  anesthesiology; and other professional services, such as oxygen therapy  and hospital-mandated on-call service. However, states varied considerably in  how service utilization was distributed within service categories, as was  shown in figure 1. Ancillary: Of total services, adult per beneficiary utilization of ancillary  services ranged from 37 percent in Rhode Island to 65 percent in  Washington and Illinois—a difference of about 28 percentage points. For slightly more than half of the selected states, total service utilization  among adults was higher for partial-year beneficiaries—those in  comprehensive managed care plans for less than the full-year of 2010. Specifically, in 11 of the 19 states, the number of services utilized per  year ranged from 2 to 78 percent higher for partial-year beneficiaries than  for full-year beneficiaries. 2.) 3.) E/M: Of total services, child per beneficiary utilization of E/M services  ranged from 29 percent in Minnesota to 45 percent in Georgia and  Rhode Island—a difference of 16 percentage points. For example, for all but one state, the number of  services utilized per year was 4 to 44 percent higher for partial-year child  beneficiaries than for full-year child beneficiaries. 4.) Agency Comments

We provided the Secretary of Health and Human Services with a draft of  this report. The Department of Health and Human Services provided  technical comments, which we incorporated as appropriate. We presented service utilization patterns for adults and children by state,  by service category, and by the length of beneficiary enrollment—in  particular, whether beneficiaries were enrolled in a comprehensive  managed care plan for a full or partial year. Based on our analysis of encounter data, the number of professional  services utilized per beneficiary per year reported by the 19 selected  states for adults enrolled in comprehensive managed care plans in 2010  ranged from about 13 to 55; the range for children was generally lower,  from about 6 to 16.
Why GAO Did This Study

Medicaid, a federal-state health financing program for low-income and medically needy individuals, covered 65 million beneficiaries at an estimated cost of $508 billion in fiscal year 2014. More than half of Medicaid beneficiaries are enrolled in managed care plans, a health care delivery model where states contract with managed care organizations to provide covered services for a set cost. Historically, states have submitted relatively unreliable managed care service utilization data, also known as encounter data, to the Centers for Medicare & Medicaid Services, the federal agency that oversees Medicaid. However, recent evidence suggests that encounter data may be improving. Information on beneficiaries' service utilization could serve as a baseline for future analyses of utilization trends over time. GAO was asked to examine the level of services provided to these beneficiaries. In this report, GAO describes what encounter data indicate about the service utilization of Medicaid beneficiaries in managed care plans.
To do this work, GAO analyzed state-reported data included in CMS's 2010 Medicaid Analytic eXtract data and determined that 19 states had data that were reliable for its purposes, but excluded the remaining 31 states and the District of Columbia. For these 19 states, GAO calculated service utilization rates for adult and child beneficiaries enrolled in comprehensive managed care plans by state, service category, and length of enrollment. GAO received technical comments on a draft of this report from HHS and incorporated them as appropriate.

What GAO Found

Based on GAO's analysis of 2010 encounter data reported by 19 states, the number of professional services utilized by adult beneficiaries ranged from about 13 to 55. For children, the number of professional services utilized per beneficiary was lower, ranging from about 6 to 16 among the 19 states. Professional services included four categories of services: (1) evaluation and management (E/M) services, such as office visits and emergency room and critical care services; (2) procedural services, such as surgery and ophthalmology; (3) ancillary services, such as pathology and lab services; and (4) other professional services, such as oxygen therapy.
States varied considerably in how service utilization was distributed within service categories. For example, of total services,
adult per beneficiary utilization of ancillary services ranged from 37 percent in Rhode Island to 65 percent in Washington and Illinois; and
child per beneficiary utilization of E/M services ranged from 29 percent in Minnesota to 45 percent in Georgia and Rhode Island.
Service utilization for both adult and child beneficiaries also varied by the length of enrollment. When compared with beneficiaries enrolled for a full year, total service utilization for adults was 2 to 78 percent higher for partial-year beneficiaries—those enrolled in a comprehensive managed care plan for less than the full year—in slightly more than half of selected states. For children in all but one selected state, service utilization was 4 to 44 percent higher for partial-year beneficiaries compared with full-year beneficiaries.