September 2018 Medicaid & CHIP Enrollment Data Highlights

The September 2018 Medicaid and CHIP Application, Eligibility Determinations, and Enrollment Report represents state Medicaid and Children's Health Insurance Program (CHIP) agency activity for the month. The report is one of a series of reports on state Medicaid and CHIP data, and it includes point-in-time data reported by states. Updated Medicaid and CHIP application, eligibility determinations, and enrollment data is available on

As with previous reports, this month’s report contains preliminary data and includes data for all states on the following indicators (the term "states" includes all 50 states and the District of Columbia):

  • The number of applications submitted directly to Medicaid and CHIP agencies, including those received through State-Based Marketplaces (SBMs);
    he number of eligibility determinations made by Medicaid and CHIP agencies on the applications described above, as well as applications to the Federally-Facilitated Marketplace (FFM) in states for which the FFM makes an eligibility assessment (and the state then completes the Medicaid or CHIP determination); and
     he total number of individuals enrolled in the Medicaid and CHIP programs who are receiving comprehensive benefits, including details on the total number of children enrolled in these programs.

Read additional background information about the monthly enrollment report

Highlights from the September 2018 Report

Medicaid & CHIP Total Enrollment

bar chart state map72,966,179 individuals were enrolled in Medicaid and CHIP in the 51 states reporting September 2018 data. 66,421,583 individuals were enrolled in Medicaid and 6,544,596 individuals were enrolled in CHIP (please see contextual information below regarding CHIP enrollment). More than 15.3 million additional individuals were enrolled in Medicaid and CHIP in September 2018 as compared to the period prior to the start of the first Marketplace open enrollment period (July - Sept. 2013), in the 49 states that reported relevant data for both periods, representing more than a 27.1 percent increase over the baseline period. (Connecticut and Maine aren't included because they did not report data for both periods). View graph of Medicaid and CHIP Enrollment Growth over Baseline.

Medicaid Child & CHIP Total Enrollment

people and bar chartNearly 35.3 million individuals are enrolled in CHIP or are children enrolled in the Medicaid program in the 48 states that reported child enrollment data for September 2018. Children enrolled in the Medicaid program and individuals enrolled in CHIP make up nearly 50.7 percent of total Medicaid and CHIP program enrollment. View graph of Medicaid Child and CHIP Enrollment.

Important Contextual Information

  • Not all states are included in each of these figures due to missing data. Also, some states included in these figures report data that deviate from CMS's specifications. For a listing of state-specific notes and data quality limitations, please see the full report.
  • Other sources of enrollment data, including data from the Statistical Enrollment Data System (SEDS) and Medicaid Budget and Expenditure System (MBES), may not align with the enrollment data included in this report because of methodological differences. For example, in the most recent published SEDS annual enrollment report, CHIP enrollment was reported as nearly 9.5 million. Unlike the point-in-time, monthly enrollment counts included in this report, the SEDS CHIP enrollment figure represents the number of individuals ever enrolled in CHIP throughout the year. SEDS total and state-specific annual enrollment data.
  • All states reported enrollment data for September 2018; however, only 49 states reported both September 2018 enrollment data and data from July-September 2013. These 49 states reported total enrollment in September 2018 of nearly 71.9 million individuals, and July-September 2013 average enrollment of more than 56.5 million. For September 2018, CMS is reporting growth of 15,323,985 compared to July-September 2013 in the 49 states reporting data for both periods.  
  • Virginia signed into law its plan to implement Medicaid expansion on January 1, 2019.
  • The July-September 2013 data may contain individuals with retroactive Medicaid coverage, and the September 2018 data included in this report is preliminary. Therefore, the difference reported here between September 2018 and July-September 2013 period is likely understated.