Analysis of Recent National Trends in Medicaid and CHIP Enrollment

This data note looks at national and state-by-state Medicaid and CHIP enrollment data through May 2021, as the COVID-19 vaccine became much more widely available to adults ages 16 and older and the number of COVID-19 cases and deaths were decreasing prior to the widespread emergence of the Delta variant. After declines in enrollment from 2017 through 2019, total Medicaid/CHIP enrollment grew to 82.8 million in May 2021, an increase of 11.5 million from enrollment in February 2020 (16.2%), right before the pandemic and when enrollment began to steadily increase (Figure 1).1 Increases in enrollment reflect changes in the economy (as more people experience income and job loss and become eligible and enroll in Medicaid and CHIP coverage) and provisions in the Families First Coronavirus Response Act (FFCRA) that require states to ensure continuous coverage to current Medicaid enrollees to access a temporary increase in the Medicaid match rates. While enrollment has increased for 15 consecutive months, the monthly increases appear to be slowing compared to April through August 2020, when monthly increases were the largest. However, continued economic uncertainty and fallout from the more transmissible Delta variant could impact future Medicaid enrollment trends.

The information in this data note is based on KFF analysis of the Centers for Medicare and Medicaid Services (CMS) Performance Indicator Project Data. Medicaid/CHIP enrollment data are submitted monthly by state Medicaid agencies and, with each monthly update, states often revise the previous months’ enrollment to include retroactive enrollment and to better align with reporting criteria. Except for the latest month’s enrollment (May 2021), this brief reports data from the updated enrollment reports for all other months to reflect the most current enrollment data possible. However, the data presented in this brief will differ from those presented in monthly Medicaid and CHIP Enrollment Snapshots published by CMS, which use exclusively preliminary enrollment reports for all months.

Medicaid/CHIP enrollment increased following the implementation of the Affordable Care Act (ACA) but was declining in the two years prior to the pandemic. Following the implementation of the ACA Medicaid expansion to low-income adults in 2014, there were large increases in Medicaid and CHIP enrollment across states that followed steady growth in coverage of children over the past decade. These increases reflected enrollment among newly eligible adults in states that implemented the expansion as well as enrollment among previously eligible adults and children due to enhanced outreach and enrollment efforts and updated enrollment procedures tied to the ACA. This trend began reversing when enrollment started to decline in 2018 and continued to decline in 2019. Total enrollment fell from 73.4 million in December 2017 to 71.2 million in December 2019, a decline of 2.2 million people or 3.0%. Month-to-month enrollment declines slowed but continued until February 2020. The declines in enrollment, in part, reflected a robust economy, but experiences in some states suggested that they may have also reflected enrollment losses among people who were still eligible for coverage due to challenges completing enrollment or renewal processes.

Data show that Medicaid/CHIP enrollment is increasing amid the coronavirus pandemic as data from February 2020 to May 2021 show that enrollment increased by 11.5 million or 16.2%. Recent increases could reflect new enrollment related to changes in the economy and job loss, as well as eligibility and enrollment requirements included in the Families First Coronavirus Response Act (FFCRA), also known as maintenance of eligibility (MOE) requirements. Under the FFCRA, to be eligible for enhanced federal Medicaid matching funds, states must ensure continuous coverage for those enrolled in Medicaid as of March 18, 2020 and cannot make eligibility and enrollment more restrictive than policies in place as of January 2020. Over this period, all states experienced Medicaid/CHIP enrollment growth ranging from 10.5% to 32.2% (Figure 2).

Virtually all growth was concentrated in Medicaid, which grew by 17.5% (11.3 million enrollees) from February 2020 to May 2021 data (Figure 3).
Conversely, CHIP has seen very little enrollment growth since February 2020 (2.9%, or 195,000 enrollees), and several states (16) have seen declines in CHIP enrollment from February 2020 through May 2021 reports.2 These declines in CHIP enrollment for some states could reflect changes in family income, causing children to move from CHIP to Medicaid coverage. As discussed below, all states reported increases in child enrollment for Medicaid/CHIP overall during this time period.

Reflecting economic changes and provision in FFCRA, adult enrollment in Medicaid/CHIP has increased rapidly during the pandemic, growing by 21.8% from February 2020 through May 2021 enrollment reports (Figure 4). This growth amounts to an additional 7.5 million adults in the 49 states and DC that report adult/child monthly enrollment (Arizona does not report children or adults separately). Additionally, three states began newly enrolling expansion adults in 2020 (Utah and Idaho in January, Nebraska in October), which may also be contributing to increased adult enrollment. Child enrollment grew as well, but at a slower pace: 10.6% or 3.7 million enrollees in the same period. Still, every state reporting these data saw an increase in child Medicaid/CHIP enrollment during this time period, despite declines in CHIP enrollment in some states (as discussed above).

Enrollment may continue to grow while the MOE remains in place for Medicaid and due to the effects of ACA open enrollment. There is usually a lag between unemployment and Medicaid enrollment growth, so even if unemployment starts to decline, there may continue to be Medicaid enrollment growth. Current enrollees will not be disenrolled due to the MOE that will remain in place during the public health emergency period that was just extended into January 2022. Medicaid/CHIP enrollment reports are lagged by approximately four months, so future Medicaid/CHIP enrollment reports may also show further increases stemming from the Biden administration’s implementation of a special enrollment period for the federal ACA Marketplace that was in place from February 15 through August 15, 2021 as well as the regular open enrollment period for the ACA Marketplace beginning November 1, 2021. The ACA Marketplace provides a single application for Medicaid, CHIP, and Marketplace coverage, and many people visiting the Marketplace during open enrollment will qualify for Medicaid or CHIP coverage. The return to in-person schooling in the fall may have also increased Medicaid/CHIP enrollment through school-based outreach and enrollment programs. Additionally, two states, Oklahoma and Missouri, implemented Medicaid expansion in late 2021 and will add to enrollment in forthcoming reports. Finally, future enrollment reports may also show how Medicaid enrollment was affected by the Delta variant and ongoing economic changes.

  1. Medicaid/CHIP enrollment reports are submitted monthly by state Medicaid agencies, reflecting enrollment on the last day of the month. With each update, states often revise data for the previous month(s) to better align with reporting criteria, such as including retroactive enrollment or other criteria. May 2021 data are preliminary and subject to change; all other months presented in this brief are based on updated enrollment reports. The data presented in this brief differ from those reported in monthly “Medicaid & CHIP Enrollment Snapshots” published by CMS, which use exclusively preliminary enrollment reports for all data reported.

    ← Return to text

  2. The 16 states with declines in CHIP enrollment from February 2020 through preliminary May 2021 represent all types of CHIP programs, including Medicaid expansion programs (M-CHIP, 3 of 9 states), separate CHIP programs (S-CHIP, 4 of 13 states), and states administering a combination of the two (9 of 29).

    ← Return to text

The Henry J. Kaiser Family Foundation Headquarters: 185 Berry St., Suite 2000, San Francisco, CA 94107 | Phone 650-854-9400
Washington Offices and Barbara Jordan Conference Center: 1330 G Street, NW, Washington, DC 20005 | Phone 202-347-5270 | Email Alerts: | |

Filling the need for trusted information on national health issues, the Kaiser Family Foundation is a nonprofit organization based in San Francisco, California.