Medicaid Enrollment Data Collected Through MBES

For the quarter beginning with January 1, 2014, states began reporting Medicaid enrollment data as part of their Medicaid expenditure reporting through the Medicaid Budget and Expenditure System (MBES). The enrollment information is a state-reported count of unduplicated individuals enrolled in the state’s Medicaid program at any time during each month in the quarterly reporting period. The enrollment data identifies the total number of Medicaid enrollees and, for states that have expanded Medicaid, provides specific counts for the number of individuals enrolled in the new adult eligibility group, also referred to as the “VIII Group”. Reports linked below include state-by-state data for this population as well as a count of individuals whom the state has determined are newly eligible for Medicaid. Recently, states began reporting Medicaid new adult group expenditures to CMS through MBES on the Form CMS-64.

Quarterly Medicaid Enrollment Data - New Adult Group

These data have been transitioned to Data.Medicaid.gov to allow sorting, filtering, and sharing. You can download the data as an Excel file by following the link to your desired dataset, then selecting the “Export” button in the top right of the dataset. In the “Download” menu, select “CSV for Excel.”

About the Reports

State Medicaid expenditure reports are generally submitted to CMS within 30 days following the end of each quarter (e.g., the expenditure report for January 1, 2014 – March 31, 2014 was due April 30, 2014). Some states, however, submit their expenditure reports later. Further, the enrollment data is a new element of the MBES report and states are continuing to adjust their systems to provide the new data elements, which can result in a delay before data is available to be released publicly.

When states submit their Medicaid expenditure reports, they certify the data are accurate and CMS conducts a limited review to assess whether the data is reasonable. The review consists of comparing the state-reported data to other readily available information, including state-reported performance indicators and expenditures, and follow-up with the state as needed. Data collection through the forthcoming T-MSIS system (which will use the same definition as the MBES report) will undergo a more thorough quality review and will serve as the authoritative enrollment data. MBES provides preliminary reporting of this data. 

The MBES data may not perfectly align with other sources of enrollment data, including data obtained from states through the Medicaid and CHIP Performance Indicator process. The differences between the MBES data and Performance Indicator data may result from one or a combination of various factors, including but not limited to, the following:

  • The MBES data and the Performance Indicator data rely on different definitions of enrollees. Examples of these differences include:
    • The MBES count includes individuals enrolled in limited benefit plans and the Performance Indicator count does not include such individuals.
    • The MBES data represents the count of unduplicated individuals enrolled in the state’s Medicaid program at any time during each month in the quarterly reporting period, while the Performance Indicator data captures the count of individuals enrolled on the last day of the month.
    • The MBES count only includes individuals whose coverage is funded through Medicaid (title XIX of the Social Security Act), while the published Performance Indicator also includes individuals funded through CHIP (title XXI of the SSA).
  • MBES and Performance Indicator data may be derived from different state systems.
  • Retroactive state adjustments to MBES or Performance Indicator data may be in progress.
  • States have likely generated MBES data and Performance Indicator data from state systems on different dates. 

Once reviewed, the enrollment information for each state will be posted to this page. States have the opportunity to update their enrollment data with each quarterly expenditure report submission for up to a year. When a new quarter of enrollment data is posted, the enrollment data for the previous three quarters will also be updated. As we progress through the first year of this new enrollment reporting, we are continuing to work with states to promote timely and accurate information.