Medicaid Expansion Spending and Enrollment in Context: An Early Look at CMS Claims Data for 2014

Appendix A: Comparison to Other Available Data Sources

Spending. States have historically reported expenditure data through the MBES for claiming purposes; this is sometimes referred to as CMS-64 data. However, the expenditure data in this report may differ from other data reported from the MBES due to differences in timing as well as adjustments made to the data. For example, expenditure data from the MBES is commonly reported on a Federal Fiscal Year (FFY) basis (October 1 – September 30) whereas the data in this report reflect the calendar year (January 1 – December 31).

Enrollment Data. Since December 2013, CMS has been providing another source of monthly enrollment data for Medicaid and CHIP as part of its Medicaid and CHIP Performance Indicator Project. There are important differences between the Performance Indicator and MBES enrollment data that limit the ability to make comparisons between the two datasets, as discussed below and highlighted in Appendix Table 1:

  • The data vary in their intended purpose. The MBES enrollment data are collected as part of the claiming process for federal Medicaid matching funds only, not CHIP. The Performance Indicator data are intended to provide timely insight into Medicaid and CHIP eligibility and enrollment trends to support program management and oversight.
  • There are key differences in who is included in the enrollment data. The MBES enrollment data include all enrollees whose spending is eligible for Medicaid matching funds (including limited benefit waiver enrollees and Medicare enrollees that receive cost-sharing and premium assistance from Medicaid). In contrast, the Performance Indicator enrollment data only include enrollees that receive full benefit coverage. Moreover, the MBES enrollment data only include enrollment in Medicaid and not CHIP; the claiming process for CHIP, which has different matching rates, is done separately. The Performance Indicator data include enrollment for both Medicaid and CHIP.
  • There are differences in the timing of the data. The MBES data include individuals enrolled in the state’s Medicaid program at any time during the month of the reporting period. In contrast, the Performance Indicator data are a point-in-time count based on the number of individuals enrolled as of the last day of the month. The MBES enrollment data cover the period between January and June 2015 (though only data through December 2014 is used in this analysis), while the most recent monthly Performance Indicator report included data through October 2015.
Appendix Table 1: Differences Between CMS MBES and Performance Indicator Enrollment Data
MBES Data Performance Indicator Data
Eligibility Groups included All Medicaid enrollees, including those receiving limited benefits (e.g., limited benefit waiver enrollees and Medicare enrollees receiving cost-sharing and premium assistance from Medicaid). Does not include CHIP enrollees. Includes enrollees in Medicaid and CHIP enrollment. Does not include enrollees receiving limited benefits.
Enrollment data period Total number of enrollees ever enrolled during the month. (Data are reported on a quarterly basis.) Total number of enrollees as of the last day of the month.
Frequency of reporting Quarterly Monthly
Most recent data available as of December 2015 June 2015 (only data through Dec 2014 are used in this analysis) October 2015
Data purpose Collected as part of the claiming process for federal Medicaid matching funds. Collected as part of new Medicaid and CHIP Performance Indicator Project to inform program management and oversight.
Issue Brief Appendix Table 2: Total Medicaid Expenditures, CY 2014

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