Fact check: Which states have the highest number of residents enrolled in ACA plans?

1. Numbers that grab attention: which states top the list and by how much?

Three independent tables and analyses list the same five states at the top, though the precise counts differ because they reflect different reporting periods and aggregation methods. The 2024 Open Enrollment report lists Florida ^{[4] [5] [6]}, Texas ^{[7] [8] [9]}, California ^{[10] [11] [12]}, North Carolina ^{[10] [13] [14]}, and Georgia ^{[10] [15] [16]} as the top five by selections or auto‑reinstatements during the 2024 Open Enrollment Period ^[1]. A 2025 KFF data snapshot and accompanying KFF analysis report higher totals for the same five states — Florida ^{[4] [17] [18]}, Texas ^{[7] [19] [20]}, California ^{[10] [21] [22]}, North Carolina ^{[23] [24]}, and Georgia ^{[10] [25] [26]} — showing substantial year‑over‑year growth in raw enrollment counts ^{[2] [3]}. The consistency of state ranking across datasets underscores that absolute enrollment concentrates in large, populous states, with Florida and Texas far ahead of others.

2. Why the numbers differ: timing, methodology, and re‑enrollment mechanics

Variation across the cited figures reflects differences in the reporting window (2024 Open Enrollment vs. 2025 totals), whether the counts include automatic re‑enrollments or only plan selections, and whether datasets aggregate Marketplace plans only or combine Marketplace and Medicaid expansion figures. The 2024 Open Enrollment report explicitly counts consumers who selected or were auto‑re‑enrolled during the OEP, producing the lower but methodologically specific totals ^[1]. KFF’s State Health Facts snapshots and analyses often report updated annual totals that capture subsequent administrative adjustments and broader enrollment flows, yielding higher cumulative counts for 2025 ^{[2] [3]}. These methodological differences mean apparent discrepancies are methodological, not contradictory, and both point to the same ranking of top states.

3. Bigger picture: enrollment has surged, and politics and policy matter

All cited analyses document large growth since 2020, with KFF noting that Marketplace enrollment has more than doubled since 2020 and that the fastest growth occurred in states carried by President Trump in 2024 ^{[27] [28]}. KFF’s thematic reporting ties much of the enrollment expansion to policy changes and economic factors, while another KFF analysis highlights that states which adopted the Medicaid expansion see larger ACA‑related coverage shares, linking state policy choices directly to enrollment outcomes ^[29]. This broad pattern indicates that federal policy, state expansion decisions, and recent federal outreach and subsidies are core drivers of rising enrollment, not random demographic shifts.

4. Where viewpoints diverge and what critics emphasize

KFF analyses and the Open Enrollment report present convergent facts but emphasize different narratives: one highlights political geography of growth (fastest increases in Trump‑won states), suggesting outreach and coverage gaps being closed in those regions ^[28], while others focus on Medicaid expansion as the structural explanation for higher enrollment shares ^[29]. Stakeholders with policy agendas may therefore emphasize either partisan gains or policy design. The data permit both readings simultaneously: absolute enrollment is concentrated in large states, and policy choices amplify coverage gains, so partisan and structural explanations are both supported by these datasets ^{[27] [29]}.

5. What to watch next: data updates and policy levers that will change rankings

Future enrollment tallies will shift with annual Open Enrollment periods, policy changes to premium subsidies, state decisions on Medicaid expansion, and outreach/auto‑enrollment rules. KFF’s ongoing updates and the annual Marketplace Open Enrollment reports are the primary sources tracked here; the most recent documents cited show consistent state rankings but evolving totals ^{[1] [2] [3]}. Analysts and policymakers should prioritize comparisons that match reporting windows and inclusion rules before drawing conclusions about trends, because apparent jumps can reflect counting method changes rather than sudden population movements ^{[3] [1]}.

Sources: KFF marketplace and enrollment reports and the 2024 Open Enrollment report, as cited in the analysis excerpts ^{[3] [27] [28] [1] [2] [29]}.