What racial and ethnic groups are most and least likely to be enrolled in ACA marketplace plans or Medicaid today?
Executive summary
Black and Hispanic people are sizable shares of ACA Marketplace and Medicaid populations, but exact “most” and “least” likely groups vary by program and state; CMS and KFF report large Marketplace enrollment growth with demographic breakouts available in CMS public-use files and KFF state tables [1] [2]. Marketplace enrollment hit about 24.2–24.3 million in 2025, and CMS’s 2025 Open Enrollment Report says plan selections trended younger and include self‑reported race/ethnicity data for detailed analysis [3] [4] [1].
1. Who the federal data can actually tell us right now
CMS publishes 2025 Marketplace public‑use files that include self‑reported race and ethnicity for plan selections, making it possible to identify which racial/ethnic groups enroll in Marketplace plans and in what numbers; the files cover all 50 states plus DC with some differences by state platform [1]. The Health Insurance Exchanges 2025 Open Enrollment Report summarizes those plan selections and explicitly notes demographic trends — for example, selections “trended younger” — and documents the share of consumers receiving premium and cost‑sharing help [4].
2. Large-scale enrollment shifts that change the racial/ethnic picture
Marketplace enrollment more than doubled since 2020 and reached a record ~24.2–24.3 million people in 2025, concentrated heavily in Republican‑won states and non‑Medicaid‑expansion states — dynamics that reshape which racial and ethnic groups appear in Marketplace rolls because state populations and expansion choices differ across groups [5] [3] [6]. KFF’s state data tools likewise provide race/ethnicity breakdowns by state for plan selections, enabling comparisons across groups and geographies [2].
3. What existing sources say about racial/ethnic shares (and what they don’t)
KFF maintains Marketplace plan selection by race/ethnicity tables for 2025 that let researchers identify which groups are more or less represented in Marketplaces at the state level, but the summary materials in our results do not quote national percentage shares directly — the KFF indicator is available for look‑up [2]. CMS’s PUFs contain self‑reported race/ethnicity fields, but our sources do not extract or summarize national race/ethnicity percentages from those files in prose here; the raw PUFs are the referenced data source for exact numbers [1] [4].
4. Medicaid’s racial and ethnic footprint: state expansion matters
Medicaid enrollment patterns by race and ethnicity are heavily shaped by which states expanded Medicaid. Analyses note that non‑expansion states have relied more on Marketplaces (with 20% of populations in non‑expansion states ever enrolled in an ACA Marketplace plan versus 12% in expansion states per a Treasury briefing), implying Medicaid’s racial composition can differ markedly where expansion occurred or not [7]. The 2025 CMS report and HHS analyses document large enrollment shifts but the provided sources do not include a concise national race/ethnicity ranking for Medicaid enrollees in 2025 [4] [8].
5. Competing interpretations and where to look for precise rankings
One view: Marketplace growth concentrated in Republican or non‑expansion states likely increased enrollment among demographic groups that are large in those states (for example, Hispanic populations in Texas and Florida), so Marketplace shares of some groups rose with geography‑driven enrollment gains [3] [5]. Alternative view: national aggregates could still show Black or non‑Hispanic White enrollees as large absolute groups because of population distribution and historical enrollment patterns; resolving this requires the CMS PUF or KFF state indicators for exact shares [1] [2].
6. Practical next steps to get the exact “most” and “least”
To name which racial/ethnic group is "most" or "least" likely enrolled in Marketplace plans or Medicaid today, consult:
- CMS 2025 Marketplace Open Enrollment public‑use files for plan selections by self‑reported race/ethnicity (download and aggregate national totals) [1].
- KFF’s Marketplace plan selections by race/ethnicity indicator for state‑level comparisons and national summaries [2].
- CMS’s Health Insurance Exchanges 2025 Open Enrollment Report for context on who received subsidies and age trends while you parse race/ethnicity fields [4].
7. Limits, agendas and why numbers can shift quickly
Public reports emphasize that policy choices — enhanced premium tax credits from ARPA/IRA that run through 2025 — drove Marketplace growth; if those subsidies change, the racial/ethnic composition of enrollments could shift rapidly, especially in states with large Hispanic or Black uninsured populations [6] [5]. Note the implicit agenda of federal and advocacy releases: highlighting enrollment gains supports arguments for subsidy extensions, while state‑level reporting can be used to bolster local political claims about program impact [6] [3].
Sources cited above contain the underlying data needed to produce precise national and state rankings by race and ethnicity; available sources do not present a single, quoted national list of "most" to "least" likely racial/ethnic groups in Marketplace plans or Medicaid within the materials provided here [1] [2] [4].